Role of Computed Tomography in Evaluation of Different Causes of Intestinal Obstruction Correlated With Operative Findings

Intestinal obstruction is a common clinical problem that occurs secondary to mechanical or functional obstruction of the intestine, preventing normal transit of its contents. It is a frequent cause of hospitalization and represents 15-20% of surgical admissions for acute abdominal pain .

The underlying aetiology of large bowel obstructions (LBOs) is age dependent, but in adulthood, the most common cause is colonic cancer (50-60%), typically in the sigmoid. The second most common cause in adults is acute diverticulitis (involving the sigmoid colon). Together, obstructing tumors and acute diverticulitis account for 90% of all causes of LBO.

Adhesions are the most common cause of small bowel obstruction (SBO) , For practical purposes, they do not tend to cause LBO.Other causes which cause symptoms that are mimic intestinal obstruction as in bowel ischemia that mainly caused by mesenteric vessels occlusion (adynamic obstruction).

Computed tomography (CT) has become a mainstay in diagnosing bowel obstruction. This is because the management of obstruction has dramatically changed with a decrease in the proportion of patients who need surgery Multi Detector Computed Tomography scanners provide a huge gain in performance that can be used to reduce the scan time, reduce section collimation, or to increase scan length surgery.

Diagnosis of intestinal obstruction is established by patient history and clinical findings include abdominal distension, acute abdominal pain, vomiting and inability to pass stools or flatus .

The role of CT in diagnosing intestinal obstruction has been expanding by determining presence, degree, level and cause (extrinsic lesions, intrinsic lesions, intussusception, intraluminal lesions) of obstruction and in identifying any associated strangulation, and also it has an important role in diagnosing the mesenteric vessels obstruction by thrombi by injection of IV contrast media which causes adynamic bowel obstruction .