BOWEL OR FAECAL INCONTINENCE IS THE INABILITY TO PREVENT RECURRENT LEAKAGE OF FAECES FROM THE anus. It is one of the most embarrasing and distressing medical conditions, and not surprisingly, majority of sufferers refuse to talk about it, avoid medical consultations and try very hard, albeit unsuccessfully, to hide it. Surveys have shown that 10% of the normal population has some form of faecal incontinence, being much more common in women than men. It is a major problem in children born with physical and neurological abnormalities, in patients with spinal cord injury, in nursing homes, in the elderly and in the terminally ill.
Anal continence is maitained by a specially evolved set of muscles called the anal sphincter whic is controlled by the spinal cord and the brain. Damage to the sphincter, the nerve supply, the spnal cord and the brain can cause incontinence. By far, the commonest cause of anal sphincter and nerve injury is childbirth. It is detected in 30% of vaginal deliveries especially of very large babies and after prolonged labour, forceps delivery and vaginal and rectal tears. Sympoms of faecal incontinence often manifest many years after the injury, when the pelvic floor and sphincter muscles become weaker with age. Incontinence often progresses from inability to hold flatus (or wind), to liquid stools and finally to solid stools, the most severe form.
In the past, not much could be done for faecal incontinence apart from medications to make liquid stools solid, regular enemas to keep the rectum empty and frequent changes of diapers. The lack of effective treatments available when patients consulted their doctors made them evn more frustrated.
Today, we have a much beter understanding of the physiology and pathology of faecal incontinence. Furthermore, many more effective treatmetns are now available. In Singapore, the first anorectal phsiology laboratory to study faecal incontinence was set up in the Department of Colorectal Surgery, Singapore General Hostpital in 1989 under Dr Ho Yik Hong who is now the Professor of Surgery a the James Cook University Medical School in Townsville, Australia. |
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The anatomical structure of the anal sphincter, the function of the nerves, the capacity and vollume that the sphincter can hold can now be clearly elucidated. This enables a more rational and systematic approach to treatment. If the anal sphincter is damaged or torn, as seen birth injury or major road traffic accidents, it can be repaired surgically, the common procedure is Anterior Sphincter Repair. If the spincter function is intact but weak, it could be enhanced by injecting a "bulking" material into the anal canal to enable it to close more tightly. This is similar to the treatment for urinary incontinence by urologists. The bulking material could be collagen, carbon granuels or some inert fibres. Worldwide, this is the most common procedure used for incontinence. It is effective in correctly selected patients, it is easy to perform, it has low rate of complications and it can be repeated. It is not suitable for very severe incontinence but it has made tremendous difference to patients quality of life. It has given confidence to patients who were previously afraid to go out of the house or to go on holiday for fear of not knowing where the next toilet is located.
With more severe incontinence from nerve damage and weak muscles, an effective treatment is Sacral Nerve Stimulation which uses a nerve stimulator, like a heart pace-maker, that is inserted around the nerves in the lower back. Stimulation of the nerves will lead to contraction of the pelvic floor muscles including the anal sphincter, creating continence. To defaecate, the stimulator is switched off.
When there is no anal sphincter function, artifica sphincters can be installed surgically to provide continence. There are two main types: One uses the thight Gracilis muscle and the other uses a cuff and reservoir system to wrap around the anal canal. Even in the very best centres in the world, these procedures are only 60% effective and they require complex, staged surgeries which carry a high complication rate especially of infection. They are also very expensive procedures. They are not widely used today. A new technique of inserting a special magnetic ring around the anus is being assessed. Early results are encouraging and it is relatively easy to install surgically. Hopefully, it will prove to be an effective treatment for patients with severe incontinence who would otherwise require permanent diapers or permanent colostomies. |
