The effect of whole-gut lavage on colon motility and gastrocolic response in a monkey

The effects of thorough colon lavage on fasting electrical control and response activities, as well as on muscular contractions, were recorded from the right, transverse, mid, and left colon of four conditioned monkeys. The gastrocolic response of monkeys to feeding is most prominent in the right and transverse colon in both duration and frequency of contractions. The response is reduced in midcolon and is just discernible in the left colon in fasted but otherwise unprepared animals. After lavage of the colon, a gastrocolic response to feeding is vigorously present throughout the colon. The removal of colonic content by lavage also leads to an increase in the duration of the gastrocolic response. These experimental observations are consistent with the results noted in humans in similar although less systematic experiments. Although the mechanism is unknown, the presence of stool in the lumen appears to blunt the contractile gastrocolic response of the colon to feeding.