Bariatric surgery: a review of normal postoperative anatomy and complications.

The number of bariatric surgery procedures performed is increasing every year. Patients may be referred for radiological investigations to exclude complications not only in the early postoperative period but many months later. Radiologists who do not work in bariatric centres are therefore required to have an understanding of the complex normal anatomy and complications associated with bariatric surgery to interpret imaging studies correctly. The purpose of this article is to describe the surgical techniques and normal anatomy of the four bariatric operations performed today, review the most common problems encountered in this patient group, and to describe the imaging findings that allow the accurate diagnosis of complications. In particular, we focus on identification of the internal hernia, a grave complication of bariatric surgery often missed by radiologists.