Fecal incontinence may occur with any cause of diarrhea, especially if the diarrhea is severe or the patient weak.

Causes of fecal incontinence and rectal discharge
- diarrhea: rectovesical and rectovaginal fistulas
- fecal impaction with overflow: neurogenic
- rectal tumors: spinal cord lesions
- proctitis: sacral nerve root lesions
- rectal or pelvic surgery

The complications of fecal incontinence include anal pain and discomfort, pruritus, and maceration or excoriation of the perianal skin that predisposes to ulceration.
It may also cause considerable psychological distress with feelings of shame or disgust caused by loss of control over bowel function and the need for frequent washing and changing.
Clinical assessment usually indicates the cause. Rectal examination will disclose impaction, rectal disease, or neurological abnormalities. Further investigations are rarely necessary.

Woodruff R. Palliative medicine evidence-based symptomatic and supportive care for patients with advanced cancer. 4th ed. Oxford University Press, 2004. p. 255.