Health Articles

Loss of voluntary control of defecation. Continence requires rectal and anal sensation to detect rectal filling and to discriminale among fluid, feces, and flatus: the reservoir capacity of the rectum and distal colon to store feces for variable periods of time; and the coordination of the internal and external anal sphincters to prevent unwanted defecation. The pelvic floor muscles, especially the puborcctal muscle, preserve continence by retarding stool passage by mechanical means. The motivation to maintain continence is also important, especially among the elderly because cognitive dysfunction is more prevalent. The causes of fecal incontinence in elderly persons are listed in TABI.F. 55-5.
The effects of impaired contractile strength of the puborectal muscle or the external anal sphinclcr become more important as rectal visco-elaslieity and resting pressures of the internal anal sphincter decrease with aging. Because a given volume of rectal distention elicits higher rectal pressures, rectal urgency is experienced a! smaller distention volumes. Furthermore, smaller distention volumes are able to inhibit anal sphincter tone. All of these changes predispose the elderly lo fecal incontinence and add stress to the striated muscles of the anoreclum.
In institutionalized, physically or mentally impaired elderly patients, (he
most common cause of fecal incontinence is leakage of liquid stool around an impacted fecal mass. Fecal incontinence probably results from a failure to sense rectal volumes that are large enough lo inhibit the internal anal sphincter. Thus, these palienls do not consciously contract Ihe striated muscles to prevent incontinence. Anal sphincter pressures are usually normal after disimpaction. In patients with global dementia, fecal incontinence may occur after meals or other activities that stimulate Ihe gastrocolonic response because (hese palienls simply do not suppress Ihe urge to defecate.
In ambulatory, noninstitutionalized elderly patients, fecal incontinence is often associated with abnormal anorectal continence mechanisms, which may involve decreased conlraclile strength or impaired automa-ticity of Ihe puborectal and external anal sphinclcr muscles. These changes may result from age-related muscle weakness; however, in elderly women, they often resull from a partial denervation injury from pudendal neuropathy. In many women with a diagnosis of idiopathic fecal incontinence, the injury to the pudendal nerve appears to be even more severe; this injury is associated with prolonged nerve conduction and evidence of a dcnervalion-reinnervation injury to the external anal sphincter or puborectal muscle.
The cause of pudendal neuropathy is unknown. Suggested causes include repetitive stretching of the pudendal nerves in middle-aged and elderly women because of chronic constipation and defecatory straining, weaker pelvic floor muscles caused by a hormonal effect, and spondylitic compression of nerve roots.
Diagnosis
Patients wilh fecal impaction and incontinence do not require extensive testing. However, incontinent persons without fecal impaction require a comprehensive evaluation of possible underlying causes. This evaluation usually includes diagnostic studies to assess anorectal continence mechanisms such as proctosigmoidoscopy, barium enema, proctography, and anorectal manometry (sec TABLE 55-6).
Treatment
After removal of a fecal impaction, treatment continues with daily or twice-daily enemas. Because failure (o empty Ihe colon increases the risk of recurrent impaction, colonic irrigation wilh huge volumes of a balanced electrolyte solution can be used after initial enemas. After the colon is cleansed, immobilized or functionally impaired patients should be placed on a restricted fiber diet and have enemas administered once or twice weekly to prevent recurrenl soiling.
In nonconstipated, intact elderly patients, biofeedback techniques, drugs, and surgery may be used to treat incontinence.
Biofeedback is a simple and often effeclive treatment for incontinence associated wilh rectosphincteric abnormalities. An anorectal manometer attached to a visual display allows Ihe patienl lo see when sphincteric responses are appropriate; the patienl then tries lo reproduce Ihe appropriate response. In essence, biofeedback is a trial-and-error learning process. Many elderly palienls have difficulties because of anxiety ahoul the procedure and short-term memory loss.
However, the technique has been successful in up to 70% of patients who meet the criteria for biofeedback (motivation, ability to comprehend and remember directions, and some degree of rectal sensation), including patients with incontinence caused by prior sphincter surgery or anorectal diseases, idiopathic incontinence, and diabetes mellitus. Similar results have been reported when patients use an intra-anal plug containing two electrodes attached to an electrometer. With this device, electrical impulses generated by the contracting anal sphincter provide the patient with audible or visual feedback concerning sphinc-teric responses.
For fecal incontinence associated with chronic diarrhea, opiate derivatives are often helpful. Studies suggest that loperamide is superior to codeine and diphenoxylate in reducing incontinence. When incontinence is associated wilh impaired reservoir capacity or with neurogenic abnormalities affecting colorectal function, a program of planned regular defecation and fiber restriction to reduce slool volume often reduces incontinence. If incontinence persists, loperamide can be taken. The dosage (maximum 16 mg/day in divided doses) is titrated to decrease stool frequency or eliminate defecation altogether. To prevent fecal impaction when defecation is eliminated, enemas should be administered once or twice weekly.
When fecal incontinence is associated with rectal prolapse, surgery is the procedure of choice. Rectal prolapse is caused by an intussusception of the rectum through the pelvic floor; resuspension or proctopexy can prevent furl her intussusception and can he combined with rectosig-moidectomy to restore continence in up to 2h of patients. However, when prolapse is severe or prolonged, permanent neuropathic sphincter impairment may preclude a good surgical result.
For patients who have fecal incontinence without full-thickness rectal prolapse, surgery should be considered if conservative therapy is unsatisfactory. However, the decision to treat surgically and the choice of surgical procedure must be made carefully because none of the procedures is easy to perform or without complications. Also, few controlled studies have compared the long-term outcomes of the various procedures wilh those of conservative treatment. In one study, 65% of Ihose who underwent surgery had a successful outcome compared with 40% of those who received nonsurgical treatment. However, biofeedback techniques were nol used in this study. When surgery is selected, the procedure should be designed to correct abnormal continence mechanisms identified by preoperative studies.

Diarrhea and colonic inflammation that occurs dnrint; or shortly after the administration of antibiotics or chemotherapy.
The vast majority of cases are mediated by a cytotoxin produced by Clostridium difficile: this cytotoxin triggers epithelial necrosis and a characleristic inflammatory process. C. difficile, the most common agenf of nosocomial diarrhea, is acquired most often by elderly persons in hospitals or nursing homes. Nosocomial transmission involving environmental contamination with C. difficile and carriage of the organism on the hands of hospital personnel has been documented. Acquisition of C. difficile is often asymptomatic, but it may have clinical consequences if elderly patients receive certain antibiotics or chemolhera-peutic agents. Other possible risk factors include surgery, intensive care, nasogastric intubation, and length of hospital stay. Some patients have antibiotic-associaled diarrhea without evidence of C- difficile infection.
Although almost all antibiotics have been implicated, cephalosporins, extended-spectrum penicillins (eg, ampicillin), and clindamycin arc implicated most often. Other penicillins and erythromycin arc involved less often.
Symptoms and Signs
The disease spectrum ranges from mild diarrhea (with little or no inflammation) lo severe colitis often associated with pseudomembranes, which adhere lo necrotic colonic epithelium. The typical clinical pic-lure of antibiotic-associaled colilis includes watery nonbloody diarrhea, lower abdominal cramps, fever, and leukocytosis. Fever is usually low grade, although occasionally it can be high. In severe cases, dehydration, hypotension, hypoproteinemia, toxic megacolon, or colonic perforation may occur. When diarrhea occurs without colilis, constitutional symptoms are usually absent.
Diagnosis
Diagnostic studies are used to define anatomic and histopathologic changes and to identify the causative organism. Certain tests can identify C. difficile or its toxin. The tissue culture assay for a cytopalhic toxin neutralized by specific antitoxins is the standard, but many hospitals lack the facilities for these assays and must submit slool specimens to reference laboratories. The preferred alternative is an enzyme immunoassay that yields results comparable to the tissue culture assay. Stool cultures for C. difficile require selective growth media, and inexperienced laboratories have reported difficulties in recovering the organism. Moreover, whether C. difficile can be implicated in antibiotic-associated diarrhea without idenlifying the cytotoxin is unknown.
In general, endoscopy should be performed in severely ill patients who present alypieally and require a rapid diagnosis to expedite Ireal-menl. In severely ill patients, flexible sigmoidoscopy is usually satisfactory because the dislal colon is involved in most cases. However, changes may be confined to the right colon in up to ‘A of cases, making colonoscopy necessary when less extensive procedures do not confirm adiagnosis that is strongly suspe-clcd. The yellowish-gray pseudomembranes are dense and adhere to the underlying colonic mucosa, but the mucosa between !hc pseudomembranes appears normal. When pseii-domembranes are not grossly visible, mucosal biopsies may exhibit characteristic findings. Barium x-rays and computed tomography are less useful. Barium enemas should be performed gently to reduce the risk of colonic perforation.
Treatment
In patients with C. t/iXrVc’/e-assoeiated diarrhea or colitis, the implicated drug should be stopped, if possible. If symploms persist or the disease is clinically severe, patients should receive metronidazole 500 mg orally bid for 7 to 14 days or vancomycin 125 mg orally qid for 7 to 14 days. If oral administration is not possible, metronidazole 500 mg IV q 6 h should be given until oral administration is possible. Metronidazole and vancomycin appear to be therapeutically comparable, but metronidazole costs substantially less. However, if the patient is seriously ill, oral vancomycin is usually recommended. Fever usually resolves within 24 h, and diarrhea decreases over 4 to 5 days.
Relapse rates average 20% to 25% after successful treatment with either agent. Patients who have one relapse arc more likely to have another. This phenomenon cannot be explained by antibiotic resistance but may involve sporulation, which leads to relapse within 4 wk after successful treatment. Relapses invariably respond to another course of antibiotic therapy. In the 5% to 10% of patients who have multiple relapses, metronidazole or vancomycin in conventional doses should be followed by a 3-wk course of cholestyramine 4 gm tid and/or laclobacil-lus 500 mg orally qid, or vancomycin 125 mg orally every olher day. The efficacy of a nonpathogenic yeast, Sacchciromycex houlardii, is being investigated, and preliminary results appear promising.

Impairment of blood supply to the colon then results in inflammation and edema.
The colon is supplied with blood mainly by branches of the superior and inferior mesenteric arteries; collateral circulation, particularly by the marginal artery of Drum mond and arc of Riolan. is extensive. Thus, if a major artery is occluded, collateral vessels open immediately to maintain an adequate blood supply to the bowel. Colonic ischemia may result from a generalized reduction in blood flow (nonocclusive ischemia), from inadequate distribution of blood flow (ie. vessel obstruction wilh poor collateral circulation), or a combination of the two. The splenic flexure is the most vulnerable point in the colon; about 80% of ischemic colitis occurs there. Colonic ischemia is the most common vascular disorder of the intestines in Ihe elderly; it is often misdiagnosed unless it is strongly suspected and an aggressive diagnostic approach is used.
In most cases, the cause of colonic ischemia cannot be established wiih certainty and no vascular occlusions can be identified. In a significant minority of patients, a potential obslruclion, such as a benign stricture, diverticulitis, or carcinoma, is found in the colon. Other contributing factors include hypotension, dehydration, heart failure, use of digitalis, polycythemia, volvulus, and cardiac arrhythmias.
Symptoms and Signs
The clinical manifestations of colonic ischemia arc varied. The most common presentation is the sudden onset of mild to moderately severe cramping pain in the left lower abdomen. Often, this pain is accompanied by bloody diarrhea or hemalochezia that may not appear until 24 h later. Frank hemorrhage is not characteristic of ischemia. Physical examination reveals tenderness over the involved bowel. In about 2h of patients, tenderness occurs over !he splenic flexure or the dislal transverse or descending colon. Peritoneal signs may las! for several hours; if they last longer, a bowel infarction may have occurred. Fever, leuko cytosis, absence of bowel sounds, and abdominal distention also suggest the possibility of bowel infarction.
Ischemia may be classified as reversible or irreversible. Reversible ischemia may present with submucosal or intramural hemorrhage or transient ischemic colitis, which completely resolves within weeks to months, depending on the severity. Irreversible ischemia may present with chronic ulcerations, strictures of varying lengths, colonic gangrene, or fulminant transmural colitis.
Recurrent episodes of colonic ischemia occur in < 10% of patients. Attempts should be made to correct or remove underlying conditions that predispose patients to colonic ischemia.
Diagnosis
If colonic ischemia is suspected clinically, a gentle barium enema or colonoscopy with minimal insufflation of air should be done within 48 h. Barium studies may show thumbprinting in the affected areas of the colon, which represents submucosal or mucosal hemorrhages during early ischemia. This thumbprinting corresponds to the purplish blebs seen on colonoscopy. X-ray findings from later stages of ischemia include segmental ischemia, which may or may not return to normal within weeks or months; this finding corresponds to segmental necrosis, inflammation, ulcerations, or mucosal sloughing on colonoscopy. Mesenteric angiography is not useful in patients with colonic ischemia in contrast to those with suspected mesenteric ischemia of the small intestine.
Treatment
Treatment includes bowel rest, IV fluids or plasma expanders, and in severe cases, systemic antibiotics such as gentamicin and clindamycin. Corticosteroids are not beneficial and should not be given. In mild disease, symptoms resolve within several days, and radiologic healing usually occurs within several weeks, although some patients may not heal for up to 6 mo.
If the patient continues to have diarrhea, bleeding, or significant obstructive symptoms for more than several weeks, surgical resection is usually indicated. If colonic infarction is suspected, emergency laparotomy with resection of nonviable bowel is required.

A chronic Inflammatory process of unknown cause ilia! most often affects the terminal ileum or colon and that is characterized by transmural inflammation, often with linear ulcerations and granulomas.
Histologic examination reveals transmural inflammation affecting all layers of Ihe bowel and often associated with submucosal fibrosis. Other features that distinguish Crohn’s disease from ulcerative colilis are linear ulcerations, fissures, fistulas, discrete mucosal ulcers, granulomas, and skip areas. Unlike ulcerative colitis. Crohn’s disease frequently does not affect the rectum. The disease can involve any area of the Gl iract from the mouth to the anus but mosl oflen involves the ileum and colon. Crohn’s disease confined to the colon (Crohn’s colitis) occurs more oflen in the elderly ihan in younger persons, and left-sided colitis appears to be prevalent in elderly women.
Symptoms and Signs
The clinical picture in the elderly is similar to that in younger persons; it includes rectal bleeding, diarrhea, fever, abdominal pain, and weight loss. In patients with colorectal involvement, perianal disease, a feature of Crohn’s disease, may be an early manifestation. A person wilh perianal disease may present with rectal or anal strictures, fissures, fistulas, abscesses, prominent skin tags, or ulcers. The prevalence of extraintestinal manifestations such as migratory arthritis, pyoderma gangrenosum, iritis, and erythema nodosum is similar in older and younger patients. Common laboratory abnormalities such as leukocytosis, hypoalbuminemia, elevated erythrocyte sedimentation rate, and abnormalities indicating anemia vary with ihe severity of the illness. Rarely, the patient presents with peritonitis caused by bowel perforation, although it is more common with ileal involvement. An elderly patient with peritonitis may present atypically with mild abdominal pain, few abdominal findings, and mental confusion. Uncommonly, a patient wilh Crohn’s colilis presents with massive lower Gl bleeding or bowel obstruction.
Diagnosis
Prolonged delays in diagnosis probably occur more often in the elderly. A possible explanation is that Crohn’s colitis, which is common in the elderly, tends to present more indolently than ileal or ilcocolonic involvement.
Because ihe rectum is often unaffected and the distribution in the colon is often discontinuous, colonoscopy and barium x-ray are the diagnostic tests of choice. Both procedures can identify Ihe charaeterislic ulcerations, skip lesions, and areas of colonic narrowing. Barium studies are better able to identify fistulas to adjacent visceral organs, whereas colonoscopy provides belter visualization of the mucosa and allows mucosal biopsies to he taken. Biopsies should be taken from mucosa that appears grossly normal and from affected areas. Biopsies help to distinguish Crohn’s colitis from diseases that mimic it. Such differentiation is particularly important because diverticula arc common in the elderly and because ischemic colilis often occurs in a discontinuous distribution.
Computed tomography provides heller definition of the colonic wall than colonoscopy and can identify extraintestinal abdominal abnormalities such as abscesses in patienls with fever or palpable masses. Computed tomography and ultrasonography may also identify renal lithiasis and ureteral obstruction, which often occur silently.
Venereal disease, which is uncommon in the elderly, and carcinoma, which may complicate long-standing Crohn’s proctitis, should be excluded. Infectious agents should be excluded by appropriate skidies.
Treatment
Treatment of Crohn’s disease is based on its extent, severity, distribution, and complications. Medical therapy includes all the drugs used for ulcerative colitis: in some patients, sclccled antibiotics are also useful (see TAUl.h; 55-4).
Ileocolitis and colitis: Patients with mild to moderate disease often respond to sulfasalazine: those who cannot tolerate it may respond to one of the newer 5-ASA drugs. Dosages are similar to those used for ulcerative colitis. If the patient responds inadequately to5-ASA drugs and the disease remains mild or moderate, metronidazole 125 to 250 mg tid may be tried before immunosuppressive agents.
If the disease worsens despite conservative therapy or if the patient has moderate to severe symptoms, prednisone 20 to 30 mg bid is given, followed by conversion to a single morning dose when disease activity significantly lessens. After remission is induced, the prednisone dose should be reduced by 5 to I0 mVwk until it is 20 mg/day. Subsequently, the dose should be tapered about 5 mg/day every 3 wk while clinical activily and laboratory parameters are monitored until Ihe patient is weaned.
About 60% of patients who cannot be weaned from oral corticosteroids respond to azathioprine (up !o 2 mg/kg/day) or mercaptopurine (up to 1.5 mg/ky/day). A therapeutic response may not develop for 6 to 9 mo. These drugs may be continued indefinitely, but at least one attempt to discontinue them should be- made after I yrol (herapy lo determine if remission can be maintained.
Perianal disease: Perianal fistulas and abscesses can be debilitating and frustrating to treat. Although perianal disease often improves with standard therapy for bowel inflammation and control of diarrhea, perianal symploms persist in some patients. Short-term success has been reported with metronidazole 1.5 to 2.0 gm/day: however, side effects are common at these doses, and relapses occur when the drug is stopped or the dosage is tapered. Ciprofloxacin 500 mg bid, a more expensive allernative, also has a high relapse rate. II an abscess develops. it should be incised and drained.
If perianal disease does not respond to (herapy, the colon may be diverted surgically, but surgery may also fail lo heal the disease. Azathioprine or mercaptopurine may be useful in some palients with refractory disease.
Surgery: Unlike ulcerative colitis. Crohn’s disease is not cured by surgery. Therefore, surgery should be reserved for patients who do not respond to medical therapy.
For palients wilh extensive Crohn’s colitis, proctocolectomy with ileostomy is the best surgical option. For elderly palients who are debilitated or malnourished, an initial subtotal colectomy with ileostomy is less debilitating: it also gives the palienl an opportunity to gain weight and to improve physically. If a subsequent proctectomy is required, the risk of complications is reduced: if rectal disease is mild or absent, a proctectomy may not be needed. More limited colonic resections may be appropriate if severe disease is localized or if obstruclive symptoms are caused by relalively circumscribed bowel involvement.
Palients with small bowel disease may require laparotomy for intestinal obstruction, peritonitis, abscess formation, or occasionally for a suspicion of malignancy. Indications for surgery in older palients with Crohn’s disease are the same as those for younger patients.
Surgery for ileal disease is generally well tolerated in the elderly, and the prognosis is comparable to that in younger patients. Elderly patients wilh extensive colitis or severe ileocolitis have higher morbidity and mortality, especially when emergency surgery is needed.
Recurrence rates after surgical resection for Crohn’s disease vary; this variation is related in part (o the initial site of disease. Proximal extension of distal colonic disease appears to be uncommon in older patients, and data suggest that recurrence rales are lower in older patients than in younger ones. Mortality rales associated with Crohn’s disease do not appear to be significantly higher in the elderly.

A chronic inflammatory process of unknown cause I hat affects the superficial layers of I In, colonic wall in a continuous distribution.
Histologic examination reveals diffuse ulcerations, epithelial necrosis, depletion of goblet cells, and polymorphonuclear cell infiltration extending from the superficial layers of the colon to the niuscularis mucosa. Crypt abscesses are characteristic but no( pathognomonic. The inflammatory process invariably involves the rectum and extends prox-imally for variable distances but not beyond the colon.
Symptoms and Signs
Symptoms in the elderly are similar to those in younger persons. Ulcerative colilis may be classified as mild, moderate, or severe (see TABLE 55-2). Most patients have diarrhea with or without blood in the stool, although older patients occasionally present with constipation or hematochezia. Systemic manifestations occur during more severe attacks and indicate a poorer prognosis. Though the disease may be less extensive in older patients, they present with a severe initial attack more often and have higher mortality and morbidity rates than younger patients.
Extraintestinal manifestations of ulcerative colitis include arthralgias, erythema nodosum, pyoderma gangrenosum, uveitis, and migratory polyarthritis. These conditions are usually associated wilh increased disease activity and occur less often in ulcerative colitis than in Crohn’s disease.
Complications
Toxic megacolon is a serious complication of ulcerative colitis that occurs more often in elderly patients. Abdominal n-rays show colonic dilation; palienls may be confused and have high fever, abdominal distention, and overatl deterioration.
The risk of developing colorectal cancer is about nine times greater in elderly patients with ulcerative colilis than in elderly persons in the general population. The risk increases substantially in patients of all ages about K y rafter the onset of the disease; carcinoma almost always develops after many years of even quiescent disease. The risk is greatest in those wilh universal colitis. Carcinoma occurs at an earlier age in patients with ulcerative colitis than in the general population. For these reasons, despite some shortcomings in the interpretation of biopsies and in the outcome of surveillance programs, all patients with longstanding ulcerative colitis should have an annual colonoscopy wilh biopsy to detect mucosal dysplasia, which is considered a premalignant lesion in ulcerative colilis. Biopsies should be taken randomly throughout the colon and in areas that appear suspicious. If high-grade dysplasia is found, proctocolectomy is indicated.
Diagnosis
The diagnosis is made by sigmoidoscopy and rectal mucosal biopsies because the disease always involves the rectum. The extent of Ihe disease is determined by colonoscopy or barium x-ray; both procedures should be avoided inpatients who are severely ill because of Ihe risk of perforation and toxic megacolon. The characteristic findings are diffuse erythema, granularity, and friability of (he mucosa without intervening areas of normal mucosa (skip areas). Inflammatory pseudo-polyps indicate more severe erosion of (he mucosa and must be distinguished from true polyps.
Diseases that may mimic ulcerative colitis must be excluded, particularly in the elderly. These include Crohn’s disease, ischemic colitis, radiation coloproctilis, and diverticulitis. In acutely ill patients, stool cultures should be obtained to exclude infectious agents, including Salmonella. Campylobacter, Shigella, amebiasis, Yersinia, and Escherichia coii 0157:1-17. Clostridium difficile-associated diarrhea and pseudomembranous colitis should be considered in elderjy persons, particularly those who recently have been treated with antibiotics, reside in institutions, or have been recently hospitalized.
Treatment
The treatment of ulcerative colitis is based on the extent and severity of the disease (see TABLE 55-3). A number of effective drugs (eg, corticosteroids. 5-aminosalicylic acid, and immunosuppressive agents) can be administered IV, orally, or rcclally.
Severe disease: Patients with severe or fulminant disease, including toxic megacolon, should be hospitalized and receive IV hydrocortisone or corticotropin infused in fluids containing enough potassium to avoid hypokalemia. One study suggests that corticotropin is more effective in patients who have not been treated previously with corticosteroids, whereas hydrocortisone may be more effective in those who have. If corticotropin does not produce significant improvement in 2 to 3 days, IV eyelosporine may be tried, but renal function should be closely monitored, especially in the elderly. When improvement is noted, IV therapy should be replaced with oral therapy.
Moderately severe disease: Oral corticosteroids are used to achieve a remission or to sustain one after IV therapy. Therapy consists of prednisone 40 to 60 mg/day initially given in two doses, then in a single morning dose. Corticosteroids should not be used for long-term maintenance therapy because of significant side effects related to both the dose and duration of therapy. These drugs may exacerbale diabetes mellitus, heart failure, osteoporosis, and hypertension, which are common in the elderly. When the disease is controlled, the prednisone dose should be tapered rapidly lo 20 mg every morning. Then it can be tapered by 5 mg/day each week until the drug is discontinued, if the disease remains quiescent. The corticosteroid dose should be tapered while clinical activity and appropriate laboratory studies are monitored .
5-Aminosalieylates (5-ASA) should be given with oral corticosteroids. Sulfasalazine is effective and inexpensive, but its use is limited by side effects in up to 309? of patients. The side effects, which are often dose dependent, include nausea, anorexia, headache, and sometimes a generalized rash; in most cases, these effects result from the inactive sulfapyridinc carrier rather than the 5-ASA. If side effects occur, sulfasalazine should be replaced with a more expensive 5-ASA drug, such as olsalazine or niesalamine. Diarrhea is a potential side effect of all 5-ASA drugs.
Mild disease: Patients with mild disease may be treated effectively with 5-ASA drugs that can be given by mouth, by enema in patients with left-sided disease, or by suppositories in patients wi(h limited proctitis. Rectal corticosleroids are also effcclive in left-sided disease. but in general, they are not more effective than 5-ASA drugs. Because about 60% of a rectal corticosteroid may be absorbed, it is less suitable for maintenance therapy. Several poorly absorbed corticosteroid enemas and corticosteroids that do not affect Ihc adrenal-piluitary-hypothalamic axis are under investigation.
Maintenance therapy: For patients in remission, lone-term maintenance with a 5-ASA drug reduces the frequency of relapses. The usual maintenance dose of sulfasalazine < I gm bid) produces few or no long-term adverse effects. For palients who cannot tolerate sulfasalazine, olsalazine 500 mg bid with meals is effective. For those with ulcerative proctitis or left-sided colilis, 5-ASA suppositories and enemas are effective when given every night to every third night. Nonsteroidal antiinflammatory drugs have been reported to activate quiescent inflammatory bowel disease and should be avoided if possible.
Surgery: Surgery is indicated when medical therapy for acute fulminant disease fails, when patients cannot be weaned from long-term corticosteroid therapy, when surveillance studies reveal precancerous colonic lesions, and when medical therapy for chronic ulcerative colitis produces a suboptimal response.
In all age groups, the most common operation for acute fulminant colitis is subtotal colectomy and ileostomy. In elderly patients, proctocolectomy and ileostomy is the procedure of choice when long-term medical therapy fails or when premalignant changes develop. Procedures that avoid ileoslomy. such as the ileoanal reservoir, are a good choice for many younger palients. However, ihe increased morbidity rate associated with this procedure limits its use in the elderly, who are already at greater risk for fecal incontinence because of age-associated changes in anal sphincter function.

Although ulcerative colitis and Crohn’s disease are more common in early adulthood, they arc no! uncommon in the elderly, partly because more patients with inflammatory bowel disease are living into old age. Also, both diseases have a bimodal age of onset; the first occurs during the 20s, and (he second occurs between ages 50 and K(l. This pattern persists even when diseases (hat mimic inflammatory bowel disease (eg, ischemic and infectious colitis) have been excluded. The reasons for this bimodality are unknown.

Small clusters of dilated and tortuous veins in the mucosa of the colon and small intestine. Found in > 259c of those > 60 yr. vascular ectasias are an important cause of lower GI bleeding in the elderly. The main theory concerning their development is that repeated episodes of low-grade, partial obstruction of submucosal veins occur when colonic muscles contract or when intraluminal pressure increases, resulting in venous dilation and tortuosity. Mucosal veins drained by the submucosal vein may also be affected. Tn the final stage of development, the precapillary sphincter becomes incompetent, and a small arteriovenous communication with the ectatic tuft of vessels develops. Vascular ectasias usually develop in the right colon, probably because of the greater tension on the bowel wall, as expressed by Laplace’s law relating tension to the diameter of the bowel lumen. A putative causal association between vascular ectasias and aortic stenosis has been questioned after a thorough review of the literature.
Symptoms and Signs
Mucosal vascular ectasias are asymptomatic in most persons. Patients usually present with painless, subacute, and recurrent bleeding.
which stops spontaneously in ihe vast majority of cases. Bleeding may consist of bright red blood, maroon stools, or melena. or it may be occult. About 10% to \5% of patients have episodes of brisk blood loss.
Diagnosis
Diagnosis may be made by colonoscopy or angiography. Colonoscopy is preferred because it can exclude other causes of bleeding and also can be used as a therapeutic intervention. Because lesions are small, often multiple, and difficult to see, the colon must be thoroughly cleansed to allow adequate visualization of the mucosa. Cleansing is usually done after bleeding has stopped: it should be done within 48 h so that other sources of bleeding, such as diverticula or ischemia, can be identified. Meperidine should not be used to sedate patients undergoing colonoscopy because it makes identification of ectasias more difficult; if meperidine is required, naloxone can be administered during the procedure to enhance visualization.
Mesenteric angiography is preferable when acute bleeding is brisk. A finding of tortuous, densely opacified clusters of small veins that empty slowly indicates advanced ectasias. Early filling of the vein, indicating an arteriovenous communication, is found in most patients who are studied for bleeding. When bleeding is active t≥ 0 J.to 1.0 mL/min). the contrast medium is extravasated into the bowel lumen, but because bleeding is often intermittent, extravasation is seen in only a minority of patients. In such cases, scintigraphy with technetium Tc 99m red blood cells may locate a bleeding site. This technique detects active bleeding at rates of 0.05 to 0.1 mL/min. and the patient can be serially scanned for up to 36 h if bleeding is intermittent.
Treatment
Conservative treatment, consisting of blood or iron replacement as appropriate, should be used whenever possible. When bleeding is recurrent, transcolonoscopic electrocoagulation or laser coagulation may be attempted. Difficulties include identifying the ectatic lesions and excluding other causes of blood loss if bleeding has stopped. Also, perforation of the right colon is a recognized hazard of coagulation therapy.
Active, severe bleeding may be controlled quickly by intra-arterial or IV administration of vasopressin 0.2 io 0.6 u./min. This therapy often stabilizes the patient for more definitive treatment. If coagulation therapy is not technically possible or if acute bleeding cannot be controlled, surgery is required. If the right colon is the only identified source of bleeding, a right hemicolectomy is performed. However, after surgery, bleeding recurs in up to 209? of patients, who then require a more extensive colonic resection or exploratory laparotomy. Small-bowel enteroscopy may eventually reduce the need for diagnostic laparotomy in patients with recurrent bleeding from obscure sites.

Colonic diverticula are herniations of colonic miico.su through the smooth muscle layers. Diverticulosis is the presence of diverticula without infiamimition. Painful diverticular disease is diverticulosis accompanied by painful spasm or other symptoms. Diverticulitis is an infection arising from colonic diverticula.
Diverticula develop in areas where circular smooth muscle has been weakened by the penetration of blood vessels to the submucosa. Usually, diverticula are found in the sigmoid and descending colons and rarely in the rectum.
Diverticula are associated with aging, which may lead to structural weakening of colonic muscle. Diverticular disease occurs in abou! 40% of those > 65 yr and about 50% of those > 80 yr in Western countries. Diverticula have been found with increasing frequency in Western populations, probably because of increased longevity and insufficient dielary fiber. Low fiber diets may increase colonic motor activity and intraluminal pressures; therefore, fiber supplements are recommended for diverticulosis and painful diverticular disease.
The incidence of diverticulitis increases with the duration of diverticulosis. Diverticulitis develops in 15% [o 25% of persons wilh diverticulosis who are followed up s~ 10 yr. The organisms that cause diverticulitis include usual colonic flora (eg, aerobic and anaerobic gram-negative bacilli); the role of entcrococci is unknown.
Symptoms and Signs
Colonic diverticulosis is asymptomatic. Painful diverticular disease is
characterized by crampy discomfort in the left lower abdomen withoiil infection or inflammation. Symptoms often are associated with constipation or diarrhea and tenderness over the affecled areas; symptoms increase after eating and may be partially relieved by defecating or passing flatus. Kxcessivc colonic motility is the underlying mechanism producing symptoms. Symptoms of painful diverticular disease are similar to those of irritable bowel syndrome and partial bowel obslruc-tion caused by tumors or ischemia. In contrast lo diverticulitis, painful diverticular disease is nol characterized by fever, leukocytosis, or rebound tenderness.
In diverticulitis, inflammation begins at the apex of a diverliculum when the opening becomes obslructed wilh stool. Fever, leukocytosis, or rebound lendcrness indicates inflammation, which oflen remains localized in the adjacenl pericolic tissues but may progress to u perioutpatient with oral antibiotics and oral intake restrictions. If the patient is more acutely ill. the need for hospitalization will be apparent.
Surgery is recommended for patients with diverticulitis who fail to respond to medical therapy within 72 h. for many patients who have had two or more attacks of diverticulitis, for many immunocompromised patients, and for patients whose first attack occurs before age 40. The preferred procedure is a one-stage operation in which the diseased segment of bowel is resected and continuity restored by a primary anastomosis. If this procedure is not feasible, a two-stage one that requires a diverting colostomy should be used.
Before elective surgery, large abscesses often can be drained percu-taneously by an interventional radiologist using computed tomography or ultrasonography. After successful drainage and 2 to 3 wk after antibiotic therapy, surgery may be performed.
Emergency surgery is required for generalized peritonitis, persistent high-grade bowel obstruction, or rapid, unremitting GI bleeding. Elderly patients with generalized peritonitis require immediate excision of the perforation site; giving antibiotics and waiting for resolution is associated with an extremely high mortality. Most patients with complicated diverticular disease require surgery even if clinical recovery occurs because of the high risk of recurrent attacks with complications and increased morbidity.

The principal functions of the colon and rectum arc to store fecal wasle for prolonged periods and expel it appropriately. Storage is facilitated by adaptive compliance of the intestine and by contractions of colonic smooth muscle, which slow the movemenl of stool, thereby promoting water absorption and reducing stool volume. Siool moves by relatively infrequent peristaltic contractions. Defecation and continence are maintained by the ability to sense rectal filling and by the coordinated funclion of Hie internal and external anal sphincters and the pelvic floor muscles. Colonic motility and transit in healthy elderly persons are similar to those in younger persons: however, aging is asso-cialed with diminished anal sphincter lone and strength and decreased rectal compliance. The latter may increase susceptibility (o fecal incontinence in the elderly.
The major symptoms of colonic and rectal disorders are constipation, diarrhea, pain, rectal bleeding, and fecal inconlinence. Colonic and rectal disorders that occur more commonly in the elderly include diverticular disease, vascular ectasias, colonic ischemia, antibiotic-associated diarrhea and colitis, fecal inconlinence, and constipation. Inflammatory bowel diseases occur in all age groups, but new onset is more likely in the elderly and in persons in their 20s. Constipation is discussed in Ch. 56.