Spinal Cord Injury Bowel Management


Function of the Bowel System

When we eat or drink the food and fluids that are swallowed enter the stomach, where enzymes begin to break down the contents for digestion. The stomach can expand to hold between 2-4 litres of food. It is a temporary food storage area and in the process of digestion, the food goes into the stomach first before entering the small bowel (small intestine).

The bowel is the lower part of the digestive tract and its' role is to digest the food and fluids that we eat and drink, absorb the nutrients, and then to process and expel the waste products that the body cannot use.

The bowel is made up of two sections, the small bowel (small intestine) and the large bowel (large intestine).

The small bowel receives food from the stomach which has been broken down by acids and enzymes secreted by the stomach lining. The small bowel then removes nutrients from the broken down food, and passes the nutrients into the bloodstream to be processed by the liver.

From the small bowel the waste food is then passed into the large bowel, where fluid is absorbed for use by the body. As the waste moves around the large bowel it gradually forms into stools.

The waste products (stools or faeces), are then stored in the left hand side of the large bowel until they are emptied from the body at a convenient time by means of a bowel movement. A bowel movement happens when the rectum, which is the last section of the bowel is full.

As the rectum fills with stool it expands, and this triggers stretch receptors in the wall of the bowel to send messages to other parts of the body. One message triggers muscles to move the stool down through the bowel. Another message lets you know it is time to go to the bathroom by sending a message to your brain via the spinal cord, and controls the muscle at the opening of the rectum (anus). This muscle called the anal sphincter, and allows you to control when the waste (stool) leaves the body. This is often called a bowel movement or BM.

The digestive process starts at the mouth and is completed at the anus.

  • Diagram of the bowel.