This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Acute intestinal obstruction is characterized by -a) Vomiting is common in duodenal obstructionb) Pain after each attack of vomiting is characteristic of ileal obstructionc) In colonic obstruction distension is common than vomitingd) X-ray erect posture is diagnostice) Colicky pain to steady pain indicates strangulation \nSelect and explain. \nA. abc, B. ad, C. acd, D. bde', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Clinical features of small intestinal obstruction\nAbdominal pain\n\nPain is crampy in nature and tends to be more severe the distal the obstruction.\nthe pain occurs in paroxysms and the patient is relatively comfortable in the intervals between the pain.\naudible borborygmi are often noted by the patient simultaneously with the paroxysm of pain.\nthe pain may become less severe as, distention progresses, probably because motility is impaired in the edematous intestine.\nwhen strangulation occurs, the pain becomes steady and more localized without a colicky component.\n\nVomiting\n\nVomiting is almost invariable, and it is earlier and more profuse the higher (proximal) the obstruction.\nthe vomits initially contains bile and mucus and remains as such if the obstruction is high (proximal) in the intestine.\nthe more distal the obstruction, the more likely it is that vomits will become feculent. \nVomiting follows the onset of pain after an interval that varies directly with the level of obstruction.\n\nConstipation and Obstipation\n\nconstipation and obstipation will eventually occur in complete obstruction, but some stools and gas may pass initially after the onset of symptoms. In some patients diarrhea may also be seen initially, due to increased peristalsis.\n\nAbdominal distention\n\nabdominal distention occurs as the obstruction progresses and the proximal intestine becomes increasingly dilated.\nit is minimal to absent in proximal obstruction, but is pronounced in more distal obstruction.\n\nTemperature\n\nis normal or mildly elevated\n\nBlood in the stool\n\nis rare but does occur in cases of intussusception, or ischemic injury.\n\nPlain radiograph of abdomen\n\nwill show dilated small bowel loops with air fluid levels in a ladder-like pattern. These feature are absent in proximal obstruction, early obstruction or closed-loop obstruction.', 'role': 'assistant'}]