Mechanical small bowel obstruction.

A QUARTER OF A CENTURY AGO Lockwood et al. introduced a report on acute small intestine obstruction by remarking that, “The literature abounds in the description and discussion of acute small intestinal obstruction. The entity is well known; its cure is absolute; yet the mortality continues to be high.” ” Since “high” is relative I can use the same introduction for this paper. That the mortality is not as high as 25 yr ago is due to improved surgical techniques, improved preand postoperative care, and earlier and more accurate diagnosis. The last is for the most part the result of improved roentgen techniques and interpretation and is subject to further increase in accuracy. Toward this goal, it is of overriding importance that the radiologist have the benefit of as much clinical information as possible when evaluating films of a patient with suspected small intestine obstruction. Has there been previous surgery? If so, what was resected and what were the pathologic findings? Is the patient on anticoagulants; might he be bleeding for other reasons? Has there been recent trauma? Does he have a systemic disease such as pancreatitis or scleroderma? What are the bowel sounds like? Is he fibrillating? What medication has he been taking? After recognizing pertinent roentgen signs, the radiologist must then correlate them with the clinical information. His conclusions will help his colleagues opt for immediate surgery, further observation, or nonsurgical management. Prior to making any judgment about the existence of an abnormal state, one must be aware of the wide variations in normal appearance. Problems are created when normal findings simulate early abnormal findings. The normal abdomen is not always devoid of small bowel gas and may show short air -fluid levels; the colon may contain very little gas; the normal gas filled colon may resemble distended small bowel. Fortunately, the combination of distended loops and air-fluid levels or fluid filled loops of bowel, coupled with a com-