Neurogenic Bowel- The Digestive System

The Digestive System

Your bowel is part of your digestive system which has many different functions, some of which have altered due to your spinal cord injury.

The digestive system is made up of the mouth, stomach, small intestine, large intestine, rectum and anus.

Food is chewed in the mouth, then passed down to the stomach. In the stomach food is broken down (digested), and passed through to the small intestine in small amounts. Here the food is broken down into smaller particles to be absorbed through the wall of the intestine into the blood stream.

The waste material not absorbed by the small intestine and water move through to the large intestine. Water is absorbed through the wall of the large intestine. The waste material, called faeces, are propelled to the rectum. The faeces are stored in the rectum until the appropriate time for your bowels to open (or move) and evacuate the faeces.

The movement of food then faeces through the digestive system is by peristalsis, which is a wave like movement or contraction to push the contents along.

Food and fluid stimulate this peristalsis to happen automatically. Therefore the sensation to have a bowel action after a meal is more common. (This is called the gastrocolic reflex).

The control of a bowel action is by a muscle at the anus called the anal sphincter. This is a circular muscle which can be consciously controlled to relax for a bowel action to occur, or tightened to prevent a bowel action occurring until a more convenient time.

The Digestive System

Bowel:The intestine through which solid waste material of body passes.

Bowel Program:"Habit time" that has been developed, to empty your bowels.

Defaecation:Passage of the faeces out of the body.

Rectum:The lowest part of the bowel.

Sphincter:The muscle surrounding and closing the rectum.

Faecal Material:Wast products passed through the bowel.

The Digestive System

About eight litres of water enter the digestive tract each day from the diet and secretions. Most of this is absorbed by the small bowel.

About one litre of liquid enters the colon at the ileo-caecal valve.

The faeces therefore become progressively firmer as they travel towards the rectum.

Peristalsis

This is a movement consisting of a wave of contraction preceded by a wave of relaxation, which propels the contents of the intestine along.

Following A Spinal Cord Injury

When the spinal cord is damaged, messages from the bowel (including the anal sphincter), can no longer get to and from the brain via the spinal cord. Therefore you no longer have voluntary control over when you have a bowel action. When this happens, depending on the type of spinal cord injury you have, it is called an upper motor neurone lesion bowel, (a reflex bowel), or a lower motor neurone lesion bowel (a flaccid bowel).

The rectum is normally empty of faeces, but when faeces pass into it, the resulting stretch of the wall of the rectum stimulates a reflex contraction in the upper motor neurone or reflex bowel.

Bowel Management Following A Spinal Cord Injury

Following your spinal cord injury the aims of bowel management are to:

• maintain continence
• avoid bowel accidents

These aims are achieved by complete emptying of the rectum at regular intervals and at a convenient time (morning or evening). By following this simple advice, it is possible to empty your bowel regularly, and to avoid bowel motions when unwanted, so avoiding accidents.

How Do You Achieve These Goals?

Eat a regular well balanced diet. This means eating a variety of foods including:

• leafy green vegetables e.g., spinach;
• fruits (especially those with skin) e.g., apple;
• grains/complex carbohydrates e.g., bran, wholemeal bread.

These types of food act as bulk agents and absorb water to form a soft bowel action so constipation and diarrhoea are avoided.

Note: Tablets may be necessary in some case to maintain soft bowel actions.

Reflex Bowel Management

It is important to form a regular program similar to the routine you had prior to your spinal cord injury. Your body becomes very used to a constant routine. Many people will choose to comply (evacuate) their bowel every second day, while others choose to empty their bowel every day. The choice is a very individual one, suited to your lifestyle.

To achieve complete evacuation of the bowel it is important to move the contents along the large intestine, to the rectum prior to evacuation.

A good, well balanced diet may achieve this alone. Tablets may be necessary for further stimulation to increase the peristalsis, therefore moving the faeces into the rectum.

Evacuation of the rectum may be achieved by means of anal stimulation. Anal stimulation tires out the anal sphincter which then relaxes to enable emptying of the rectum.

Suppositories or enemas may also be used. These cause irritation and a feeling of fullness on the bowel wall which then stimulates emptying.

By following these procedures regularly it is possible to develop a regular, predictable bowel evacuation individually suited.

Flacid Bowel Management

Your spinal cord injury has effected the nerves which connect the messages to and from the bowel to the spinal cord. This results in a flaccid bowel. Therefore the messages do not travel to the spinal cord as the spinal cord and brain have no control over the rectum and anal sphincter. This means your rectum does not contract strongly to cause evacuation of faeces, and your anal sphincter remains loose or flaccid.

It is now necessary for you to empty your bowel by massage and abdominal expression and straining.

Massage from right to left on the abdomen will help move the faeces in the large bowel to the rectum.

Expression and straining will increase pressure on the rectum and therefore squeeze or push the faeces out.

By following these procedures regularly it is possible to develop a regular, predictable bowel evacuation suited to jour lifestyle without accidents occurring.

Factors That Effect Bowel Evacuation

A number of factors must be considered that effect bowel evacuation.

Recall, prior to your spinal cord injury, the routine you followed:

1. Sit in an upright position, on a toilet or commode. The gravity helps bowel evacuation as the faeces travel down to the rectum.
2. The bowel is an organ of habit. A regular routine should be followed to achieve bowel emptying at a regular, predictable, suitable or convenient time of the day.
3. Eating food and drinking fluids still activate the reflexes to stimulate peristalsis (the gastrocolic reflex). It is therefore important to eat a regular healthy diet.

Infections, alcohol, emotional upsets, stress and antibiotics are a few situations which may alter your bowel habits. They may cause diarrhoea or constipation.

Remember only change your routine one step at a time, and only one change per week so you may find the cause of any problems you are experiencing.

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