Small bowel obstruction: what to look for.

Small bowel obstruction (SBO) is a common clinical syndrome for which effective treatment depends on a rapid and accurate diagnosis. Despite advances in imaging and a better understanding of small bowel pathophysiology, SBO is often diagnosed late or misdiagnosed, resulting in significant morbidity and mortality. A comprehensive approach that includes clinical findings, patient history, and triage examinations such as plain abdominal radiography will help the clinician develop an individualized treatment plan. When an SBO is accompanied by signs of strangulation, emergent surgical treatment is advised. If surgery cannot be performed immediately or if a partial obstruction is suspected, then a more detailed radiologic work-up is needed. The imaging techniques used subsequently vary according to the initial findings. If a low-grade partial obstruction is suspected, volume-challenge enteral examinations such as enteroclysis and computed tomographic (CT) enteroclysis are preferred. If a complete or high-grade obstruction is suspected, cross-sectional studies such as ultrasonography or multidetector CT are used to exclude strangulation. An algorithmic approach to imaging is proposed for the management of SBO to achieve accurate diagnosis of the obstruction; determine its severity, site, and cause; and assess the presence of strangulation. Radiologists have a pivotal role in clinical decision making in cases of SBO by providing answers to specific questions that significantly affect management. (c) RSNA, 2009.