Pattern approach for diseases of mesenteric small bowel on barium studies.

Despite an array of sophisticated imaging techniques, the barium examination remains a valuable diagnostic test for evaluating structural abnormalities of the small bowel. Most patients can be examined with conventional small-bowel follow-through studies, in which periodic imaging of the entire small bowel is performed by using fluoroscopic guidance; however, some patients may benefit from enteroclysis, in which contrast agents are instilled into the small bowel via a catheter placed in the proximal jejunum for optimal distention and better depiction of individual small-bowel loops. This review for residents discusses the major diseases involving the mesenteric small bowel and presents a pattern approach for the wide spectrum of abnormalities found on barium studies, including polypoid lesions, cavitated lesions, annular lesions, outpouchings, separation of loops, abnormal folds, nodules without abnormal folds, and dilated small bowel.