Which of the following conditions occurs when the intestine is obstructed?

• A. Peritonitis
• B. Intestinal obstruction
• C. Hernia
• D. Mesenteric infarction

Answer: (B)

Intestinal obstruction is the blockage of the intestinal lumen that prevents contents from passing, leading to symptoms like crampy abdominal pain, distention, vomiting, and inability to pass gas or stool. This is the state described when the intestine is obstructed.

Peritonitis is inflammation of the peritoneum and may arise from perforation or severe inflammation; it presents with a tender, often rigid abdomen and systemic signs, but it is not the obstruction itself. A hernia is a protrusion of tissue through a defect; it can cause obstruction if the bowel becomes entrapped, but the underlying process is the herniation, not the obstruction per se. Mesenteric infarction is a vascular event causing bowel ischemia, typically with severe pain out of proportion to exam and risk factors like atrial fibrillation or atherosclerosis; this is about blood flow, not a luminal blockage.

So the condition described by the question is intestinal obstruction—the blockage that prevents normal passage of intestinal contents.