[dr.Ira]

Explanation:The correct answer is D. This patient has irritable bowel syndrome (IBS). This is the most common functional GI disorder. It is characterized by abdominal pain with alternating diarrhea and constipation. It is often related to stress or exercise. Diagnosis is made by history and thoughtful exclusion of other organic diseases. Colonoscopy, if performed, should be normal. Indication for colonoscopy would be to differentiate irritable bowel syndrome from inflammatory bowel disease.

Transmural inflammation (choice A) and fistula formation (choice B) is typical of Crohn disease. Crohn disease is characterized by inflammation of any part of the gastrointestinal tract (mouth to anus). Patients often have lesions, which are not continuous, described as skip lesions. The inflammation is transmural, which means that it involves all layers of the mucosal wall contrary to UC. Patients typically present with non-bloody diarrhea, weight loss, and abdominal pain.

Bloody diarrhea (choice C) is a finding in ulcerative colitis (UC). UC is characterized by inflammation limited to the colon and rectum and is typically described as continuous (as opposed to "skip" lesions). Bloody diarrhea is the typical presenting symptom.

H. pylori (choice E) may be a cause of abdominal pain and its eradication is recommended if it is discovered incidentally, but routine serology checks in the work-up of abdominal pain is of unproved benefit.