Physiology of the ageing gut

This article will review the recent publications (over the last 1-2 years) concerning the effects of ageing on gastrointestinal function, with an emphasis on the motor and sensory function of the gut.

Recent publications support earlier observations of an age-related selective decline in the number of cholinergic neurons in the enteric nervous system, but also reveal a progressive loss of interstitial cells of Cajal in the stomach and colon throughout adult life. These changes appear to have surprisingly little effect on gastrointestinal motor function in healthy ageing, although gut sensation is impaired and older individuals have an increased susceptibility to gastrointestinal complications of comorbid illnesses.

Alterations in gut function with ageing have particular implications in the oesophagus, colon, and anorectum. Dysphagia, gastro-oesophageal reflux disease, constipation, and faecal incontinence are the most prevalent clinical manifestations. Older individuals are also susceptible to postprandial hypotension, in which altered cardiovascular responses to intestinal nutrient exposure are pivotal. Dysphagia, delayed gastric emptying, and constipation are increasingly being recognized as early features of Parkinson's disease, and frequently precede the neurological manifestations.