This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
Diagnosis of the given XRay of abdomen: 
Select and explain. 
A. Small intestine obstruction, B. Pneumointestinalis, C. Sigmoid volvulus, D. Intussusception
C: Sigmoid volvulus
Answer: C: Sigmoid volvulus 
Explanation: Ans. (c) Sigmoid volvulusRef: SRB manual of Surgery, 4th ed. /1329* The given image shows coffee bean sign, which is seen in sigmoid volvulus.* Sigmoid volvulus is a cause of large bowel obstruction and occurs when the sigmoid colon twists on the sigmoid mesocolon.Clinical Presentation* Constipation* Abdominal bloating* Nausea and/or vomitingCauses* Chronic constipation and/or laxative abuse* Fibre-rich diet (especially in Africa)* Chagas disease (especially in South America)Treatment* Rectal tube insertion is successful in treating 90% of cases.* The most serious complication is bowel ischaemia.