Clinical, endoscopic and mucosal biopsy features of non-specific duodenitis
Inflammatory changes found in the duodenal bulb in the absence of any specific disease or duodenal ulceration has been termed non-specific duodenitis (NSD). Controversy exists about the nature of NSD and its relationship to duodenal ulcer. This thesis examines the clinical, endoscopic and mucosal biopsy features of NSD, which has been defined on the basis of endoscopic appearances and graded into mild and severe categories. Mild and severe NSD have been found to be separate entities. Severe NSD and duodenal ulcer patients were shown to have similar clinical features and gastric acid secretory capacity. Visually inflamed areas of the duodenal bulb in severe NSD and duodenal ulcer showed similar mucosal architectural changes and inflammatory cellular infiltrate. It is proposed that severe NSD and duodenal ulcer are part of the same disease process. Findings suggest that the primary damage occurs to the villus epithelial cells, with secondary increase in epithelial cell proliferation in the crypts. These studies also highlight the possible role of neutrophils in tissue damage. Mucosal changes in severe NSD and duodenal ulcer are probably characteristic of these conditions, since duodenal mucosa in groups of patients with coeliac disease, Crohn's disease and patients who had had cytotoxic drugs did not show similar changes. Mild NSD patients did not show any abnormality in mucosal architecture or cellular infiltrate. The clinical features of this group of patients were different from those with severe NSD, but similar to a group of patients with irritable bowel syndrome. It is proposed that mild NSD represents motility disorder of the upper G.I. tract, with the endoscopic findings being part of the spectrum of manifestations.