Intraluminal duodenal diverticulum (IDD) is a rare developmental anomaly usually found in the second portion of the duodenum. The cause appears to be a failure of recanalization of the occluded foregut lumen of the human embryo, resulting in a fenestrated mucosal membrane .
A small aperture in this diaphragm will gradually cause it to elongate caudally in response to duodenal peristalsis to form the so called “wind-sock” configuration.
Symptoms are nonspecific and generally depend on the degree of duodenal obstruction; 25% of cases are associated with GI bleeding. In most documented cases, IDD was diagnosed radiologically, but the value of endoscopy for diagnosis and treatment has been amply demonstrated.