The degree of sphincter defect is the main cause of fecal incontinence.

• A. True
• B. False
• C. Not sure
• D. Partially

Answer: (B)

Fecal continence depends on multiple interacting factors, not just how damaged the sphincter is. The internal anal sphincter provides baseline closure, while the external anal sphincter and pelvic floor muscles add voluntary and reflexive support. Rectal sensation and compliance, stool consistency, and the frequency of bowel movements also play crucial roles. A sphincter defect can contribute to incontinence, but many patients with sizable defects stay continent thanks to intact pelvic floor function and adequate rectal sensation, while others with minor defects become incontinent due to neuropathy, reduced sensation, or urge-related issues. Because continence results from this combination of factors, the degree of sphincter defect is not the main cause.