A patient has sustained considerable damage to his sacral spine (S2-S4) due to repeat laminectomies. What kind of bowel dysfunction can you anticipate for him?

A patient has sustained considerable damage to his sacral spine (S2-S4) due to repeat laminectomies. What kind of bowel dysfunction can you anticipate for him?

• A. Chronic constipation.
• B. Chronic diarrhea.
• C. Rapid transit of bowel contents.
• D. No bowel dysfunction.

Answer: (A)

Damage to the sacral segments S2–S4 interrupts the defecation reflex and the neural control of the distal bowel and anal sphincter. This area provides parasympathetic input to the sigmoid colon and rectum and supplies the external anal sphincter via the pudendal nerve. When these pathways are disrupted, coordinated propulsion and the urge to defecate are impaired, leading to stool retention and a tendency toward constipation. In this sacral-injury pattern, bowel movements become difficult to initiate or complete, producing chronic constipation as the characteristic dysfunction. Diarrhea or rapid transit isn’t typical here because the reflex coordination for timely evacuation is compromised, and there isn’t preserved high-tone propulsion to produce rapid stool movement. While some loss of sphincter tone can occur, the predominant pattern after sacral injury is constipation due to areflexic bowel and impaired rectal emptying.

Damage to the sacral segments S2–S4 interrupts the defecation reflex and the neural control of the distal bowel and anal sphincter. This area provides parasympathetic input to the sigmoid colon and rectum and supplies the external anal sphincter via the pudendal nerve. When these pathways are disrupted, coordinated propulsion and the urge to defecate are impaired, leading to stool retention and a tendency toward constipation. In this sacral-injury pattern, bowel movements become difficult to initiate or complete, producing chronic constipation as the characteristic dysfunction. Diarrhea or rapid transit isn’t typical here because the reflex coordination for timely evacuation is compromised, and there isn’t preserved high-tone propulsion to produce rapid stool movement. While some loss of sphincter tone can occur, the predominant pattern after sacral injury is constipation due to areflexic bowel and impaired rectal emptying.