ABSTRACT
Although the physiological changes in the ageing gastrointestinal (GI) tract can be subtle, these effects can place an older person at increased risk during illness. This chapter provides an understanding of the biological and physiological changes of the GI tract in older people and their clinical consequences. Cholecystokinin (CCK) is released in the proximal bowel in response to nutrients from the antrum, particularly lipids and proteins. Elevated levels of CCK have been demonstrated in older people and have been correlated with increased satiety and reduced hunger. Older people in their 80s and 90s have significantly decreased amplitude, but not duration and velocity, of peristaltic pressures. There is also an increased frequency of non-propulsive, often repetitive, contractions. Age-related anatomical changes in the lower GI tract might contribute to delayed transit time and delayed stool water content. Such changes may include intestinal wall atrophy reduced tone, reduced blood supply and intrinsic neuronal changes.
