Collagenous colitis associated with novel sprue-like intestinal diseases.

Almost a half-century ago, an unusual and distinct form of colitis was first recognized, collagenous colitis, characterized by sub-epithelial trichrome-positive deposits having the ultrastructural features of collagen. Later, other reports documented more extensive collagenous dis-ease in these patients, sometimes in the stomach and small bowel, a close linkage with other forms of microscopic colitis and its association with celiac and other immune-mediated diseases. Moreover, emerging genetic methods permitted large studies of collagenous colitis to complement these intriguing clinical and pathological studies. Finally, recent and related studies have further demonstrated these immune-based forms of colitis, with new sprue-like intestinal diseases caused by novel medications, recently detected viral infections and vaccinations.