A 74-year-old woman was investigated for abdominal pain and diarrhea. Endos
copic examinations including biopsies of the stomach and colon demonstrated
the typical subepithelial deposits characteristic of collagenous gastritis
and collagenous colitis. Histochemical and ultrastructural methods confirm
ed the presence of collagen in the subepithelial deposits. The topographic
distribution of these collagen deposits and their relationship to the infla
mmatory process in the stomach were then defined by endoscopic mapping and
multiple site biopsies of the mucosa in the gastric body and antrum. These
studies indicate that collagenous gastritis not only is distinctive, but al
so is a far more extensive and diffuse inflammatory process than has previo
usly been appreciated.