An investigation of colonic function in the elderly.

A straight abdominal radiograph can be used in the elderly to indicate a loaded colon. Two groups of patients were identified using radiology, one with faeces-filled caeca and the other with gas-filled caeca. Gastro-intestinal transit time measurements and breath methane analysis, an indicator of colonic bacterial activity, were used to investigate colonic function. An attempt was made to identify different colonic transit patterns by radiography after administering radio-opaque markers of various shapes on three consecutive days. Although the two patient groups showed no differences in gastro-intestinal transit time there were differences in the distribution of the pellets in the colon and in the excretion of breath methane. Straight abdominal radiography was of value in identifying two patient groups with different colonic function.