This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which of the following is not a commoner cause of intestinal perforation: March 2007 
Select and explain. 
A. Gastric ulcer, B. Gastrointestinal cancer, C. Typhoid, D. Crohn's disease
D: Crohn's disease
Answer: D: Crohn's disease 
Explanation: Ans. D: Crohn's diseasePerforation of the intestines results in the potential for bacterial contamination of the abdominal cavity (a condition known as peritonitis).Perforation of the stomach can lead to a chemical peritonitis due to leaked gastric acid.CausesUnderlying causes include:Gastric ulcerAppendicitisGastrointestinal cancerDiveiculitisSuperior Mesenteric Aery SyndromeTraumaAscariasisTyphoidOn X-rays, free gas may be visible in the abdominal cavity. The perforation can often be visualised using CT. White blood cells are often elevated.