Normal Small Bowel Findings and Variants

Abstract

The lumen of the small bowel is ringed by circular mucosal folds, the so-called valvulae conniventes (Kerckring’s folds), which gradually decrease distally. The mucosal surface is characterized by fingerlike extensions, the villi. Lymphoid follicles are scattered throughout the small bowel but are found in highest concentrations in the distal ileum. These structures can be viewed by conventional endoscopy, capsule endoscopy, or balloon-assisted enteroscopy. The characteristics of the images among those modalities are different because of the different ways of image making. In this chapter, images of normal small bowel from the endoscopy, capsule endoscope, and balloon-assisted enteroscopy will be reviewed in detail.