patients with significant colonic transit impairment and can result in fecal impaction.117 To avoid severe cramping or vomiting, defecation in severely constipated patients should be stimulated with suppositories or enemas before administering a stimulant laxative. Fecal incontinence Fecal incontinence is uncommon in the general population (2.2%) but has a significantly higher prevalence (10%) in older patients, particularly nursing home residents and hospitalized elderly patients.118, 119 Fecal incontinence can result from fecal impaction and subsequent overflow, internal anal sphincter incompetence, decreased rectal or anal sensation, or other structural impairments in the pelvic floor or anorectal neuromuscular function due to trauma or iatrogenic damage from surgery or irradiation.120 In younger patients, fecal incontinence and fecal impaction are most commonly seen in the setting of structural or neuromuscular disease. In older patients, the added risks of immobility and use of anticholinergic drugs can dramatically increase the risk of constipation and subsequent fecal impaction.121 Aging may be associated with a reduction in anal function in women.122 Healthy elderly women demonstrated thinning of the internal anal sphincter, resulting in decreased resting and maximum squeeze pressures in the anal canal.123 Although thickening of the external sphincter was also observed, this did not correlate with increased ability to maintain continence. In the absence of disease, the effects of aging on male anal sphincter function seem minimal. Other pathologic factors that contribute to fecal incontinence in the elderly are the presence of neurologic disorders that may predispose to impairment in the ability to interpret the need to defecate (dementia) or in the ability to coordinate defecation (myasthenia gravis or stroke). In addition to the social costs to the patient and family, fecal incontinence significantly increases costs to long-term care facilities.124 All patients with fecal incontinence should be assessed to determine whether increased mobilization is feasible, because immobility is a major risk factor. Medication review to identify drugs that affect colonic and rectal motility can be helpful, because both prokinetic and antikinetic drugs may worsen fecal incontinence. Drug treatment options for fecal incontinence include the following: 1 Conservative treatment with antidiarrheal agents such as loperamide in small doses titrated to reduce stool weight and slow small bowel motility.125 Unfortunately, colonic motility is also slowed and fecal impaction can result. 2 Regular administration of stimulant laxatives such as lactulose, polyethylene glycol solution, or senna. This is more likely to result in regular bowel movements than antidiarrheal medications126 but may lead to increased incontinence episodes in patients with anal sphincter incompetence or decreased anal sensation. Regular use of suppositories or enemas to ensure rectal emptying in patients with decreased colonic motility. This situation often develops in patients with an underlying neurodegenerative disease, such as Parkinson’s disease. There are limited data on the use of drugs to enhance resting anal sphincter tone (phenylepinephrine gel and valproate) suggesting that these agents may improve continence in patients with structurally intact sphincters or those with ileoanal pouches due to colectomy for ulcerative colitis.127, 128 Fiber may be helpful but when used alone may result in impaction