Most of us take it for granted that we can control our bowels. We barely have to think about controlling the release of wind (gas), or of liquid or solid (stools or faeces) from the bowel. We do not have ‘accidents’ nor are we ‘caught short’, unless perhaps we suffer a short-lived bout of diarrhoea. Sometimes, however, control is lost because the bowel or the muscular ring (sphincter) around the back passage (anus) does not function properly. Bowel contents escape. Faecal (or anal) incontinence, also known as soiling, is the loss of stool, liquid or gas from the bowel at an undesirable time. It can occur at any age and may affect up to one in 20 people. It is certainly more common than was thought some years ago. Simple tests can often show where the problem is, and treatment is frequently successful.
How do we normally control the bowel?
Normally the bowel and rings of muscle around the back passage (anal sphincter) work together to ensure that bowel contents are not passed until we are ready. The bowel contents move along the bowel gradually. The sphincter has two main muscles which keep the anus closed: the inner ring (internal anal sphincter), which keeps the anus closed at rest, and the outer ring (external anal sphincter), which provides extra protection when the urge to open the bowel is felt and when we exert ourselves or cough or sneeze. These muscles, the nerves supplying them and the sensation felt within the bowel and sphincter all contribute to the sphincter remaining tightly closed. This balance enables us to stay in control (or ‘continent’).
What causes incontinence?
Faecal incontinence occurs most commonly because the anal sphincter is not functioning properly. Damage to the sphincter muscles or to the nerves controlling these muscles, excessively strong bowel contractions, or alterations to bowel sensation can all lead to this disturbance of function.
Who suffers from faecal incontinence?
Males and females of any age may be incontinent, for example:
Children and teenagers – if they are born with an abnormal sphincter or if they have persistent constipation
Mothers, following childbirth – due usually to a tear (hidden or obvious) in
the sphincter muscles
People of any age who experience an injury or infection of the sphincter: they may be affected immediately or later in life
People suffering from inflammatory bowel disease (colitis) or irritable bowel syndrome (alternating diarrhoea and constipation together with abdominal pain) – because the bowel is very overactive and squeezes strongly
Older people – because of constipation and overflow from the bowel, or due to failing ability to get to the toilet, or due to sphincter damage persisting from a younger age.
People suffering from disorders such as multiple sclerosis, and strokes – resulting in damage to the nerves supplying the sphincter
What tests may be needed?
Tests of sphincter function are relatively simple, do not require preparation, are quick to perform and are usually pain-free. The strength of the muscles, sensation and nerve function, for example, can all be tested using simple pressure-measuring devices. An ultrasound scan can provide a clear picture of both the sphincter muscle rings, showing if one or both is damaged. This test is not uncomfortable, takes only five minutes, and involves no radiation. These tests are usually performed in units with a special interest in continence.