This patient had a confusing (and potentially misleading) clinical presentation of leukocytosis, normal lactate, and a non-concerning physical examination. The radiologist appropriately diagnosed a closed-loop obstruction, and this patient proceeded to the OR where they found "in the mid jejunum, a segment of red, injected, and dilated bowel that appeared threatened and was adherent to a dense adhesion deep in the pelvis...Once entering the abdomen, we were able to identify a single thick adhesive band which was causing the closed-loop obstruction."

The features that should immediately raise the concern of a closed-loop:

• isolated, dilated loop of small bowel
• U-shaped loop on coronal reformats
• two adjacent transition points into and out of the closed-loop segment

The transition into the closed-loop is somewhat difficult to see on axial and coronal, but well delineated on sagittal (see annotated image). The transition out of the closed-loop is easiest to see on coronal (annotated image). When trying to sort out a CLO, you must use all of your reformats! The sharp angulation/buckled appearance of the small bowel is typical for an adhesive band as the cause.