Causes. For a lot of people, there are multiple causes of fecal incontinence. Some of these causes may include damage to the nerves that provide control over the anal sphincter or the nerves that sense stool within the rectum. Another common cause is damage to the muscle rings at the anal sphincter, which might make it hard to properly hold back stool. Decreased storage capacity within the rectum is yet another cause. Usually, the rectum expands to hold stool. Diarrhea is a frequent cause as a loose stool is harder to retain than solid stool. A condition known as rectocele, in which the rectum projects through the vagina, is sometimes a cause of fecal incontinence in women. Rectal prolapse, in which the rectum descends into the anus, is another cause.
