5. DETERMINE (13–15)
7.6 OTHER GI DISORDERS .1 Fecal Impaction
Fecal impaction, which involves blockage of the colon with a hard dry stool, can lead to spurius diarrhea or seepage around the impaction. This issue may be the most common cause of diarrhea, specifically in long-term nursing home facilities (18,22). Predisposing factors which occur in older adults that lead to fecal impac- tion include decreased colonic motility, pelvic floor abnormalities, inactivity, low fiber in the diet, medications, dehydration, depression, and other comorbidities (such as Parkinson’s disease, dementia, or diabetes). Fecal impaction is usually determined by physical exam, as 70% occur in the rectum within reach on digital exam (18). The treatment includes manual disimpaction, enemas, and glycerin suppositories.
7.6.2 Ischemic Colitis
Ischemic colitis is associated with older age groups, as over 90% of cases occur in the geriatric patient population(18,23). The most common locations for ischemic colitis to occur are ‘‘the watershed’’ areas of the colon where there is poor collateral flow, such as the rectosigmoid junction and the splenic flexure. Factors which may predispose to ischemic colitis include atherosclerosis, hypotension, pelvic irradia- tion, congestive heart failure, aortoiliac surgery, infection, low-flow states, and medications (such as NSAIDs, progesterone, or digitalis) (18). Patients may Chapter 7/ Common Gastrointestinal Complaints in Older Adults 127
present with bloody diarrhea, with or without abdominal pain. The specific treat- ment for ischemic colitis involves bowel rest, broad spectrum antibiotics, and restoration of hemodynamic stability.
7.6.3 Inflammatory Bowel Disease
Inflammatory bowel disease (IBD) is common in the geriatric population as evidenced by the bimodal peak of incidence. Inflammatory bowel disease most commonly occurs in the second to fourth decade, but has a second lesser peak incidence in the sixth to eighth decade(18,24). Approximately 12% of patients with ulcerative colitiswill have onset of disease over the age of 60, while upwards of 16%
of Crohn’s disease patients will have onset of the disease over this age(18,25). One out of eight cases of IBD will be diagnosed in the geriatric population (18).
Compared to their younger counterparts, older patients are more likely to have colonic involvement, less likely to have a family history of IBD, and are more likely to respond to therapy. However, older patients will experience higher mortality due to severity of disease and the existence of comorbidities(18,26). Similar to younger age groups, geriatric patients with Crohn’s disease are more likely to have nutri- tional sequelae than those patients with ulcerative colitis. Risk factors which con- tribute to nutritional sequelae include extent of the bowel involved, length of bowel previously resected at surgery, and the type of medical therapy required to achieve remission.
7.6.4 Microscopic Colitis
Microscopic colitis is a syndrome associated with diarrhea in which the endo- scopic or radiographic evaluation of the colon is normal, but there is inflammation of the colonic mucosa seen microscopically on biopsy. Microscopic colitis is more common in females, with a mean age on presentation in the range of 55–65 years (18,27). Microscopic colitis may be precipitated by the use of NSAIDs (18,27).
Treatment is similar to that for routine IBD. Five-aminosalicylic acid agents, corticosteroids, and immunosuppressants should be used appropriately.
7.6.5 Small Bowel Bacterial Overgrowth
Small bowel bacterial overgrowth (SBBO) or blind-loop syndrome may be increased in the geriatric population. Symptoms of SBBO range from bloating, diarrhea, steatorrhea, and weight loss to specific nutritional deficiencies. Risk factors which predispose the older patient to SBBO include achlorhydria or hypochlorhydria from chronic gastritis, motility abnormalities from diabetes and scleroderma, and disruption of intestinal continuity because of formation of blind-loops postoperatively (2). These factors usually lead to over-coloni- zation of the small bowel with coliforms and anaerobes. Infestation of these organisms in turn leads to abnormalities associated with binding of vitamins, de-conjugation of bile salts, and fat malabsorption with subsequent diarrhea/
steatorrhea.
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7.6.6 Lactose Intolerance
Lactose intolerance may be increased in older adults, as lactase levels decrease with age (2,16). Across all ethnic populations, the incidence of clinical lactase deficiency can be up to 75%. Overall, 25% of adults in the United States demon- strate lactase deficiency(2,16). Symptoms are variable and include bloating, gas, and diarrhea.
7.6.7 Incontinence
Incontinence is defined by theinvoluntary passageof liquid or solid stool. Older patients in particular often misinterpret these symptoms. They assume that they are experiencing diarrhea because they cannot make it to the bathroom in time and end up soiling their clothes. A careful history may sometimes show, however, that the complaint really involves accidents where the patient simply loses continence and passes small amounts of solid or semi-liquid stool. These symptoms may be truly interspersed between otherwise normal stools. The prevalence of incontinence ranges widely in the nursing home population from 2.2% up to as high as 50%
(29). Across a general population, the overall incidence of incontinence is 4–5%, but in the geriatric population the incidence may be nearly twice that rate (up to 11–12%)(29). Clearly the prevalence of incontinence increases with age (29). In the past, incontinence has affected women more than men, but these differences may not be as great as previously thought(29). Incontinence has been known to result in perianal dermatitis, pressure sores around the perineum, and urologic infections. For the individual patient, these symptoms may result in social isolation, anxiety, depression, or loss of self-esteem. A number of predisposing factors have been identified in the literature (29). Age-related changes which predispose to incontinence include pelvic floor descent, stretch-induced pudendal nerve damage, increase in the anorectal angle, decreased rectal sensitivity, decreased anal squeeze pressure, reduced rectal reserve volume, and a lower threshold for internal anal sphincter relaxation. Comorbid conditions which predispose to incontinence include stroke, dementia, immobility, constipation, previous hemorrhoid surgery, or injury to the perineum (such as an episiotomy at the time of childbirth at a younger age)(29).
Evaluation of the patient complaining of incontinence should include a thorough physical exam of the anus and perineum with a careful digital exam. Endoscopy may be required to rule out proctitis. Anorectal manometry may be needed to evaluate the integrity of the sphincters and whether or not there is appropriate relaxation of the internal anal sphincter with distention (indicating that the rectoa- nal inhibitory reflex is intact). Endoscopic ultrasound is a newer modality which affords the opportunity to see whether there is a structural abnormality of the anal sphincters. A defecating proctogram may be required to determine whether there is an increase in the anorectal angle.
Management of incontinence includes anti-peristaltic agents such as Lomotil or Imodium. Imodium may be the superior of the two drugs, as it helps to tighten anal sphincters in addition to slowing peristalsis or motility(29). Lomotil only slows transit without affecting sphincter tone. Fiber supplementation may be important Chapter 7/ Common Gastrointestinal Complaints in Older Adults 129
to decrease the liquidity of stools. Foods which promote diarrhea should be avoided, such as caffeine, alcohol, fruit juices, beans, or broccoli. Biofeedback training may help strengthen and improve control of the external anal sphincter.
In severe cases, surgery may be required to repair disruption of the anal sphincters.
7.6.8 Constipation
Constipation may be the most common complaint in the geriatric population.
While some reports indicate that the incidence of constipation is 4–8 times more common in the older adult population than in younger controls, the incidence may not be as high in healthy ambulatory geriatric citizens(2,17). In western countries, the incidence of constipation ranges between 25 and 50%, but may range as high as 80% in nursing home residents(30,31). Constipation is more common in women than men. Symptoms associated with constipation range from decreased stool frequency and difficult passage of hard stool, to bloating, cramping, sensation of inadequate evacuation, and painful defecation(30).
There are a number of physiologic age-related changes which may predispose to constipation (2,32). Aging is associated with decreased colonic wall elasticity, impaired rectal sensation, and reduced colonic propulsion(30). There appears to be little change in colonic transit time with age however. In the majority of cases, constipation is idiopathic with no obvious underlying cause (30). However, a number of specific predisposing conditions known to occur in older adults have been identified (2,32). Functional causes for constipation include confusion, depression, immobility, and pain from anorectal fissures. Drugs such as iron, opioid narcotics, calcium antagonists, anti-depressants, and diuretics may predispose to constipation, as does longstanding laxative abuse. Endocrine etiologies which promote constipation include hypothyroidism, hypercalcemia, diabetes, and hyper- parathyroidism. Diets low in fiber, poor fluid intake, and excessive caffeine intake (causing a diuretic effect) all predispose to constipation(2,32). Mechanical issues such as diverticulosis and cancer, or gut ischemia and IBD (due to stricture forma- tion) may actually promote constipation. Clinical conditions leading to predendal nerve damage (such as diabetes, child birth, or chronic straining) may also pre- cipitate constipation(2,32).
The evaluation and management of constipation again starts with a thorough history, paying attention to diet, activities, and bowel habits. It is important to evaluate comorbidities and to identify any drugs which may contribute to constipa- tion. The clinician should question the patient on what treatment modalities have already been attempted and ascertain what degree of compliance was maintained.
The physical exam should include a digital rectal exam and visual inspection of the anus and perineum. Laboratory tests should focus on electrolyte abnormalities, iron stores, calcium metabolism, guaiac testing of the stool, glucose homeostasis, and parathyroid hormone levels. Colonoscopy may be required to rule out structural abnormalities. Treatment should include fiber supplement, increased water intake, increased activity, and avoidance of caffeine or other diuretic agents.
Bowel training, where the patient sits on the commode at the same time every day, helps to promote better contractility and increases the chance of having a bowel movement. Reviewing and revising medications may be needed as well.
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