survey of households in the United States indicated that 40.5% of respondents had one or more of these symptoms during the past month.107 Symptoms of abdominal pain and distention decrease with age in men (19.6% of men aged 18–39 years vs 7.1% of men older than 60 years), whereas elderly women continue to report significant symptoms (25.6% of women aged 18–39 years vs 20.3% of women older than 60 years). Less than half (45%) seek medical attention; therefore, the prevalence of diagnosed IBS in the population is lower. IBS is commonly thought of as a young person’s disease; however, the prevalence of diagnosed IBS in older individuals may be similar to that in younger adults108 and should be considered when other causes of constipation and diarrhea are ruled out. The pathophysiology of IBS in older patients is unclear, as it is in younger patients, but may include abnormal sensory interpretation of normal motility and decreased compliance in the colon and rectum. Treatment guidelines for younger patients are used in the geriatric population, because there are little data to guide treatment in the older cohort. Serotonin receptor antagonists developed for use in diarrhea-predominant IBS, such as alosetron, should be used with extreme caution in older patients, because several reports of ischemic colitis in geriatric-aged patients resulted in withdrawal of this agent by the Food and Drug Administration in 2000. The pathophysiology of this complication may have been related to colonic mucosal damage from prolonged stasis of bowel contents and inhibition of serotonin receptors on vascular smooth muscle that resulted in vasoconstriction. In 2002, the Food and Drug Administration allowed reintroduction of alosetron for use in women with diarrhea-predominant IBS, based on data collected in younger patients showing few complications.109 Probiotic bacterial preparations have been used to treat diarrhea-predominant IBS in younger patients110 and may prove efficacious in the geriatric population. Diarrhea Paradoxically, although constipation is far more common, diarrhea can also become a problem for many elderly patients. Diarrhea is the second leading cause of mortality worldwide111; however, in contrast to developing countries that lose far more young infants and children, 85% of mortality from diarrhea in developed countries occurs in elderly individuals.112 Infectious diarrhea is a significant cause; however, many patients are never shown to have a clear infectious etiology. Diarrhea can become a chronic problem in older patients, with tremendous implications for social isolation and decreased activity outside the home. Between 1997 and 2002, the number of hospital admissions for chronic diarrhea increased 42% to 223,310 inpatients, while office visits for chronic diarrhea increased by 115% from 991,886 to 2,132,272.4 Approximately 40% of patients with chronic diarrhea are older than 60 years, and thus this is a significant health problem in the elderly. Despite this, expenditures in 1998 by the National Institutes of Health for IBS research were the least of any GI diagnosis, namely $8.2 million. The most heavily funded areas were chronic liver disease and cirrhosis ($218.6 million), colorectal cancer ($205.2 million), hepatitis C ($66.5 million), and food-borne illness ($57.5 million).4 A subset of patients may present with new-onset fecal urgency and frequency that is similar to diarrhea-predominant IBS. The onset may coincide with