Aging of the Gastrointestinal System
This chapter addresses the following Geriatric Fellowship Curriculum Milestones: #9, #74
Understand the effects of aging on various parts of the gastrointestinal tract.
Recognize common presentations of gastrointestinal dysfunction in older adults.
Understand the effects of aging on hepatic, biliary, and pancreatic function.
Key Clinical Points
Dysmotility in the esophagus, stomach, and colon is common in older adults and is often due to a combination of effects of aging and superimposed disease.
Older patients with serious gastrointestinal (GI) disease, such as intestinal ischemia or perforation, may present with more subtle symptoms due to visceral hyposensitivity, and the severity of the condition may be underestimated.
The aging process per se has clinically significant effects on GI immunity and GI drug metabolism.
Gastrointestinal symptoms are common in patients aged 65 and older (geriatric aged) and can range from mild self-limited episodes of constipation or acid reflux to life-threatening episodes of infectious colitis or bowel ischemia. According to data from the US Census Bureau in 2005, 45 to 50 million people over age 65 had at least one GI complaint that impacted their daily life and that might result in a medical visit. Common comorbidities such as pain with nonsteroidal anti-inflammatory drug use or atrial fibrillation requiring use of anticoagulants increase the risk of gastrointestinal ulceration or bleeding. Older patients have increased prevalence of diseases such as diverticulitis and colon cancer. Geriatric-aged patients may present with unusual or subtle symptoms of serious GI disease due to alterations in physiology with aging. For example, a patient with a GI perforation or colitis may not have guarding or significant abdominal tenderness due to decreased visceral sensitivity.
The aging process has clinically significant effects on oropharyngeal and upper esophageal motility, colonic function, GI immunity, and GI drug metabolism (Figure 90-1). On the other hand, because the GI tract exhibits considerable reserve capacity, many aspects of GI function, such as intestinal secretion, are preserved with aging. Superimposed effects of chronic diseases and environmental/lifestyle exposures (medications, alcohol, tobacco) on aging-related changes can impair GI function in older patients. A modest decline in gastric mucosal cytoprotection or esophageal acid clearance may become significant when superimposed side effects of certain medications or concurrent disease are also present. Common age-related changes in GI function, such as constipation, are viewed as dysfunctional by patients and health care providers. Research areas that have been identified as important in aging include the pathophysiology of swallowing disorders, esophageal reflux, dysmotility syndromes, GI immunobiology, and the cellular mechanisms of neoplasia in the GI tract. Animal studies provide important insights into the cellular physiology of aging, despite the issue of species variation.
Effects of physiologic aging on the gastrointestinal tract. This schematic diagram summarizes significant effects of aging on various divisions of the gastrointestinal tract. Key: ...