Difference Between Visceral and Somatic Pain

Nervous System in the Abdominal Organs. The abdominal organs have two different types of pain perception: via fibers of the autonomic nervous system (ANS) originating from the intestine and peritoneum (visceral pain) and via fibers of the central nervous system (CNS) originating from the abdominal wall, including the parietal peritoneum and mesenteric portion of the small intestine (somatic pain).

Visceral Pain. The main causes of visceral pain are fast pressure increase in hollow organs, capsule tension, and intensive muscular contractions. Visceral pain is typically felt in or near the median line of the abdomen. Visceral pain of the hollow organs, primarily of the intestine, is generally characterized by colics, i. e., intermittent attacks of pain that vary in intensity, similar to labor pains, with pain-free intervals. Pain associated with visceral pain radiates to regions that belong to the same neurologic segment as the diseased organ.

Somatic Pain. Somatic pain primarily occurs as a result of irritation of the parietal peritoneum (e. g., peritonitis) or the mesenteric portion of the small intestine. This pain is localized at the site of maximum inflammation (e. g., right lower abdominal region in appendicitis) and is typically continuous. In practice, a distinction is drawn between acute and chronic or recurring abdominal pain.