Loss of bowel control, also known as faecal incontinence, can be a devastating problem. It affects men and women of all ages in up to 20% of the population. Faecal incontinence can radically affect everyday life as many people become almost house bound, being unable to undertake simple tasks, such as shopping, because they are worried about faecal leakage.
Faecal incontinence may be due to a problem with the two muscles around the anus (back passage). These muscles can be damaged or become weak due to injury during child birth or operations to treat anal conditions such as haemorrhoids (piles) and fistulas (abnormal channels between the skin and back passage). The anal muscles then become unable to hold back the stools until reaching the toilet. The inner ring or internal anal sphincter muscle keeps the anus closed at all times except when opening the bowel. A treatment has been developed to treat faecal incontinence which involves injecting a substance into or near this muscle to make it bulkier so that anus closes better. It has been advocated as a simple and safe option.
The review did not find evidence to say whether this treatment is effective or not. The four trials reviewed were of limited value because they were generally poor in methodological quality and small in size.