What is bowel incontinence?

Bowel incontinence is a condition whereby an affected person is unable to prevent involuntary passage of gas (flatus) or stools from the anus. This can be very distressing as soilage around the anus can lead to itching or burning sensations. Furthermore, the affected person may feel anxious about other people noticing the soilage. Sometimes, the sufferers are so traumatized that they withdraw socially from family and friends.

How does bowel incontinence happen?

Normal bowel continence is maintained by coordination of the nerves, and muscles of the pelvic floor and anus. When there is damage to the sensory nerves of the pelvis, the affected person may not sense the gas or stools, and that can lead to leakage of content from the anus. Damage to motor nerves can weaken the muscles of the pelvic floor and as a result, the affected person may be unable to hold back the urge to pass a bowel movement. Muscles of the anus and pelvic floor can be weakened by age, damaged by trauma or surgery to the anus, or even difficult childbirth. In many cases of bowel incontinence, it is difficult to pinpoint the exact cause as the traumatic event could have happened decades before or it could be multi-factorial.

What are the common causes of bowel incontinence?

1. Traumatic childbirth
This is the commonest cause of bowel incontinence in women. It can be difficult to diagnose early as the tearing of the anus muscles is not visible from the outside and a woman can overcome the weakness of the damaged muscles by using other pelvic muscles to compensate for the weakness. It only becomes evident with age as the rest of the pelvic muscles weaken.

2. Ageing
The general weakening of the pelvic floor muscles and anus muscles due to age can lead to an inability to shut the anus tight.

3. Nerve damage
Pelvic nerves can be damaged by surgery at the spine or pelvis, primary nerve disorders, or frequent and excessive stretching (such as chronic constipation or obesity).

4. Diabetes mellitus
One of the complications of prolonged diabetes or poor diabetic control is damage to autonomic nerves, such as the sensory nerves of the anus, and nerves to the internal anal sphincter muscles.

5. Anal sphincter damage
This usually happens secondary to surgery of the anus or anal trauma.

Can bowel incontinence be treated?

It is important to know that this condition is treatable and is not a natural part of ageing. Treatment is based on the severity of the problem(s) and cause of bowel incontinence. It is important to note that surgery is not commonly required for treatment of bowel incontinence unless the condition is very severe. The treatment usually involves modifications of lifestyle and diet, as well as anorectal biofeedback (a form of pelvic floor rehabilitation physiotherapy). Sometimes, medications are helpful to ensure a patient does not have overly hard stools or diarrhoea. There are various types of surgery and these will only be considered if conservative treatment is not enough.

Where can I find out more about bowel incontinence?

You can access the following websites for more information about the condition.

Dr Lim Jit Fong
General and Colorectal Surgeon
President, Society for Continence Singapore (2019 – Present)