[Collagenous duodenitis and ileitis in a patient with collagenous colitis].

Collagenous colitis is a disease accompanied by chronic watery diarrhea, of which the etiology is unknown. Sporadic cases of collagen deposits in the upper gastrointestinal tract are meanwhile reported. We here report the case of a 53-year-old female patient suffering from collagenous colitis with additional collagen deposits in the duodenum and ileum. The favourable effect of a therapeutical trial with bismuth nitrate is described.