Control of the GI Tract. IV. Clinical and physiological aspects of gastrointestinal motility and aging. Am J Physiol Gastrointest Liver Physiol 283: G1226-G1231, 2002; 10.1152/ajpgi.00276. 2002.-The gastrointestinal motility changes that occur as a function of age are reviewed herein. Careful attention must be given in any review of aging phenomena to exclude, or at least be cognizant of, the many comorbid conditions that can alter physiological functioning in older adults. The dramatic increase in life expectancy over the past 10-15 years demands that clinicians be aware of the various physiological and clinically relevant changes that occur with age. Gastrointestinal motility changes associated with age are relatively subtle, and in many instances only conflicting data exist. As the older adult population increases, and as the control of disease is improved, much more work needs to be done to understand the true effects of aging on gastrointestinal functioning.gastroesophageal reflux disease; dysphagia; lower esophageal sphincter; incontinence LIFE EXPECTANCY HAS INCREASED dramatically over the past 10-15 years, and the population of individuals over 65 yr old is expected to more than double by the year 2050. The projected rise in the number of Americans over the age of 85 yr is expected to increase from 4 to 18 million over a similar interval of time. As life span increases, the probability increases that individuals will acquire chronic and debilitating diseases such as osteoarthritis, Parkinson's disease, and other neurological conditions, and the risk of stroke and its debilitating sequelae is also increased. These conditions are all associated with gastrointestinal (GI) complications, particularly those related to the esophagus and swallowing. Thus age-related changes in GI functioning can be categorized in terms of those associated with these comorbid conditions of aging or those associated with the aging process itself.Relatively little work has been done to describe the GI changes associated with aging, largely due to the invasive nature of the procedures required. Thus in many instances there is a dearth of normative data on which to base clinical comparisons. For example, very little work has been done to describe normal colonic functioning, and only a few studies have been published that described normative parameters of esophageal peristalsis and lower esophageal sphincter (LES) functioning. Similar limitations apply to gastric and small bowel functioning. Studies that have been done commonly reveal conflicting results due to differences in the technology used (i.e., manometric vs. radiographic). In addition, the manometric techniques that are used vary considerably, with only the more recent studies using intraluminal solid-state transducers, which allow a much more sophisticated assessment of pressure changes compared with those that were acquired or described using more conventional and commonly applied perfusion pressure technology. These issues preclude definitive statements regarding GI func...