The Reflex and Flaccid Bowel

Bowel Care and Management Sections

•    Function of the Bowel
•    The Reflex and Flaccid Bowel
•    Methods of Bowel Management and Care
•    Possible Complications Following a Spinal Cord Injury

Function of the Bowel Following a Spinal Cord Injury

Following a spinal cord injury, damage to the spinal cord may result in the loss of the ability to control the bowel reflex when the rectum is full, or the reflex to empty the rectum may be lost altogether. The function of the bowel is maintained by the nerves entering the spinal cord at the sacral levels of S2 - S4. Due to the voluntary action of the bowel being communicated so low in the spinal cord, any spinal cord injury will usually have some impact on the defecation process.

The Reflex Bowel or Upper Motor Neuron Bowel

If the spinal cord injury is above T12, the sensation of a full bowel may no longer be detectable by the injured person. In such cases, the anal sphincter will remain closed, however, it will open on a reflex basis when the rectum becomes full.

This type of bowel is referred to as an upper motor neuron bowel reflex. As the person will not be able to sense when the rectum is full, the reflex to empty the rectum can happen at any time unless the bowel is managed properly.

The upper motor neurone bowel reflex can be managed to prevent accidental defecation, by causing the defecation reflex to occur at a socially appropriate time.

The Flaccid Bowel or Lower Motor Neuron Bowel

If the spinal cord injury is below T12, then there may be damage to the defecation reflex, and the anal sphincter muscle may relax, staying open. This type of bowel is referred to as an lower motor neuron bowel or flaccid bowel.

The lower motor neurone bowel reflex can be managed to prevent accidental defecation, by emptying the bowel more frequently at a socially appropriate time, by bearing down or the manual removal of stool.

Both types of bowel, reflex and flaccid, can be managed to avoid the accidental opening of the bowel, and to avoid constipation and impaction.

Read Next Section

Function of the Bowel
The Reflex and Flaccid Bowel
Methods of Bowel Management and Care
Possible Complications Following a Spinal Cord Injury