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
True about colonic volvulus 
Select and explain. 
A. Most common in caecum, B. Common in psychiatric pt., C. Bird's beak sign, D. May present as intestinal obstruction
B: Common in psychiatric pt.
Answer: B: Common in psychiatric pt. 
Explanation: 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