This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'Most common cause of acute intestinal obstruction is \nSelect and explain. \nA. Small bowel adhesions, B. Intussusception, C. Tuberculosis, D. Malignancy', 'role': 'user'}, {'content': "Answer: A \nExplanation: Intra-abdominal adhesions related to prior abdominal surgery account for up to 75% of the cases of small bowel obstruction. Intestinal Obstruction CausesIntraluminal (Eg. Foreign bodies, gallstones, or meconium)Intramural (Eg. Tumors, Crohn's disease - associated inflammatory strictures)Extrinsic (Eg. Adhesions, hernias, or carcinomatosis)Clinical Presentation :Colicky abdominal pain, nausea, vomiting, abdominal distension, and constipation are seen.Constipation is not seen in Richter's hernia obstruction, gallstone obstruction, mesenteric vascular occlusion.Vomiting is a more prominent symptom with proximal obstructions than distal.", 'role': 'assistant'}]