Faecal incontinence occurs when a person passes faeces (stools) without the usual control. It is a distressing condition that is actually very common although under-reported because of embarrassment. Milder symptoms may be managed by treatments such as dietary change, drugs and bowel retraining, but many patients still resort to surgery to improve symptoms. Although several operations exist to treat incontinence e.g. those aiming to repair damaged anal sphincter muscles, it is now clear that these often have poor results.