Duodenal and Jejunal Diverticulosis

This document is used to list diverticula, other than colonic. It includes developmental diverticula and acquired, as for example, jejunal diverticula. Starting at the top,

The pharynx is attached to the skull posteriorly by a fibrous band that lies posteriorly. The pharyngeal constrictor arise from thisand the fibres pass downwards and laterally. As these fibres meet the horizontal fibres of the cricopharyngeus there is the potential for a gap in the muscle wall. This dehisence allows the possibility of a herniation of the lining of the pharynx. The diverticulum, as it enlarges, lies posteriorly and then lies on the left lateral side. Occasionally, the pharyngeal diverticulum or pouch can be complicated by carcinoma, presumably from chemical changes in the food as it sits in the diverticulum. The commonest site is at the neck of the pouch.

Diverticulosis of the small-bowel is listed separate from colonic diverticulosis. Although the lumen of both is a septic environment, the main complications of small-bowel diverticulosis are due to possible effects on the absorption of nutrients. Most of the diverticula occur in the jejunum and occasionally in the duodenum. The jejunal diverticula are acquired protrusions of the mucosal lining through the muscular wall of the bowel. The individually or cumulatively may be large enough to be a separate region which encourages particular bacterial overgrowth. A combination of alteration of the intraluminal contents by these bacteria may result in malabsorption of calcium,iron, and Vitamins D or B12. (Incidentally bacterial fabrication further down the bowel may result in excretion of more Vit B12 than has been injested, particularly in Vegans). Patients may present with anaemia and occasionally osteomalacia.