The functional anorectal disorders-functional fecal incontinence, pelvic floor dyssynergia-type constipation, levator ani syndrome, and proctalgia fugax-are common but poorly understood gastrointestinal complaints. Fecal incontinence may occur in constipated patients when a fecal impaction of the rectum reflexly inhibits the internal anal sphincter and allows leakage of soft stool, or it may occur in diarrhea. Constipation-related incontinence can be treated with habit training (use of a routine time to defecate backed up by laxatives) or biofeedback to teach relaxation of the pelvic floor, but diarrhea-related fecal incontinence usually requires antidiarrheal medications. Pelvic floor dyssynergia occurs when the pelvic floor muscles paradoxically contract instead of relaxing when the patient strains to defecate. Biofeedback to teach relaxation of these muscles is effective in two thirds of patients. Levator ani syndrome involves chronic, and proctalgia fugax involves fleeting rectal pain. The cause of these painful conditions is unknown, and no treatment of proven efficacy is available.