Diffuse abdominal pain with a rigid abdomen is most consistent with which diagnosis?

• A. Appendicitis
• B. Gastritis
• C. Peritonitis
• D. Cholecystitis

Answer: (C)

A diffuse rigid abdomen points to peritoneal irritation and inflammation. When the peritoneum is inflamed, the abdominal wall stiffens in a protective, involuntary guarding response, creating a “board-like” and tense abdomen. This rigidity, especially when accompanied by diffuse abdominal pain, suggests peritonitis, a surgical emergency that often results from factors like a perforated hollow viscus or severe intra-abdominal infection.

While appendicitis can progress to peritonitis if it perforates, its typical presentation starts with periumbilical pain that localizes to the right lower quadrant, rather than a generalized rigid abdomen from the outset. Gastritis and cholecystitis usually produce more localized pain—gastric/epigastric discomfort or right upper quadrant tenderness with possible Murphy sign—instead of a global abdominal rigidity.