Lansoprazole-associated collagenous colitis: unique presentation, similar to ischemic colitis.

soprazole-associated collagenous colitis manifesting some characteristic clinical findings: chronic diarrhea, typical endoscopic findings, pathological evidence of collagen bands, and rapid clinical improvement after discontinuation of lansoprazole. We have also often encountered patients taking lansoprazole presenting with chronic diarrhea and typical endoscopic findings. Although one published article has stated that linear ulcers and ulcer scars should be considered specific for lansoprazole-associated collagenous colitis, another has not mentioned endoscopic findings at all [1,2]. However, severe ulcers rarely cause colonic perforation [3]. Here we present a patient with lansoprazole-associated collagenous colitis who presented a unique clinical picture, similar to that of ischemic colitis. A 78-year-old Japanese woman attended our emergency room because of abrupt onset of lower abdominal pain and heavy blood in her stool. She had been taking lansoprazole since 2 months and had chronic diarrhea. Initially, ischemic colitis was suspected and an abdominopelvic computed tomography (CT) scan revealed a thick-walled and edematous sigmoid colon (●" Fig. 1). Colonoscopy was performed to confirm the diagnosis and revealed a 20-cm long hemorrhagic, linear ulcer and a 15-cm linear ulcer scar in the sigmoid colon (●" Fig. 2). Histopathological examination of biopsy samples taken from the sigmoid colon showed subepithelial collagen bands (●" Fig. 3). Finally, a diagnosis of collagenous colitis was made. The cause was though to be lansoprazole and this was discontinued. Six days later, the patient was discharged with complete resolution of the diarrhea and abdominal pain. A repeat colonoscopy 2 months after admission showed healing linear lesions and scars (●" Fig. 4). No collagen bands were identified on a biopsy specimen. Lansoprazole-associated collagenous colitis: unique presentation, similar to ischemic colitis