This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
[{'content': "True about colonic volvulus \nSelect and explain. \nA. Most common in caecum, B. Common in psychiatric pt., C. Bird's beak sign, D. May present as intestinal obstruction", 'role': 'user'}, {'content': 'Answer: B \nExplanation: A volvulus is a twisting or axial rotation of a poion of bowel about its mesentery. When complete it forms a closed loop of obstruction with resultant ischaemia secondary to vascular occlusion. Volvuli may be primary or secondary.it is Common in psychiatric patients.The commonest spontaneous type in adults is sigmoid Ref: Bailey & Love&;s Sho Practice of Surgery,E25,Page-1191,1192', 'role': 'assistant'}]