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.
Surgical management of fecal incontinence
This is also termed artificial anal sphincter or neosphincter. The usual surgical approach is through the perineum or alternatively via the vagina. The artificial bowel sphincter involves the implantation of 3 components: (i) A fluid filled silicone elastomer cuff placed around the anus, (ii) a liquid filled, pressure-regulating balloon positioned in the peritoneal fat, and (iii) a manual pump connecting these components (placed in either the labia majora or the scrotum). When the cuff is inflated, the anal canal sealed. The fluid is transferred to the balloon by the manual pump, resulting in deflation of the cuff, opening of the anal canal and allowing for defecation. This procedure improves FI scores and quality of life, and continence is excellent when the procedure works (successful outcome in 85% patients with a functioning device). The procedure is less technically demanding than the graciloplasty, but there is the disadvantage of using foreign material, which can erode through the anal canal. As with graciloplasty, obstructed defecation may develop with a working device, and may be treated with enemas. Complications include infection, which may warrant temporary removal of the device. Graciloplasty and artificial anal sphincter both significantly improve continence, with artificial anal sphincter being superior, however both methods have high rates of complications.