Overview

The digestive system is a complex series of organs. These organs are all interconnected along a hollow tube that runs from the mouth to the anus. The digestive system works by digesting food, removing nutrients, returning that nutrients to the bloodstream, and then undigested fiber and waste is eliminated. The last two steps in the process concern the rectum and the anus. The rectum temporarily holds stool and then the stool is eliminated through the anus. In order to diagnose common conditions like fecal incontinence or chronic constipation, it may be necessary to determine if the rectum and anus are functioning properly.

Preparation

Follow the instructions given by the doctor in order to be properly prepared. In most cases, the patient is asked to not eat or drink anything after midnight the night before the test. The test requires bowels are empty, so an enema is prescribed two-three hours prior to the test. 

The Test

During the test, a small tube is inserted through the anus and into the rectum. Then, a small balloon at the tip of that tube is slowly inflated. When the balloon is inflated, the muscles in the anus and rectum to contract. The tube is connected to a monitoring device that records those contractions.