Fecal incontinence
Fecal incontinence (FI), also known as anal incontinence, or in some forms encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents—including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and usually there is more than one deficiency of these mechanisms for incontinence to develop. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery (especially involving the anal sphincters or hemorrhoidal vascular cushions), altered bowel habits (e.g., caused by irritable bowel syndrome, Crohn's disease, ulcerative colitis, food intolerance, or constipation with overflow incontinence), and receptive anal sex. An estimated 2.2% of community dwelling adults are affected.
Rectal prolapse
The association with uterine prolapse (10-25%) and cystocele (35%) may suggest that there is some underlying abnormality of the pelvic floor that affects multiple pelvic organs. Proximal bilateral pudendal neuropathy has been demonstrated in patients with rectal prolapse who have fecal incontinence. This finding was shown to be absent in healthy subjects, and may be the cause of denervation-related atrophy of the external anal sphincter. Some authors suggest that pudendal nerve damage is the cause for pelvic floor and anal sphincter weakening, and may be the underlying cause of a spectrum of pelvic floor disorders.