A 60s woman with frequent watery diarrhea who was urgently hospitalized with renal dysfunction. Previously she had been prescribed olmesarton and rosuvastatin by a local doctor beause her medical history included hypertension and hyperlipidemia.
Colonoscopic examination revealed edematous mucosa of the left colon and an indistinct vascular pattern. Biopsy of the same region revealed abundant lymphocytic infiltration in the mucosa, and the likely diagnosis was lymphocytic colitis. Two weeks after cessation of these medications, the diarrhea had improved. Then approximately three months after discontinuation of the drugs, colonoscopic examination showed improvement in the mucosal edema and the vascular pattern.
Examination of a biopsy specimen revealed that the pathological findings of lymphocytic colitis had also disappeared. Thereafter, treatment with olmesartan was resumed temporarily. However, it was again discontinued because the diarrhea had recurred. Subsequently these symptoms resolved. Thus, the patient was diagnosed as having lymphocytic colitis associated with olmesartan.
