Olmesartan, which is an angiotensin II receptor blocker, reportedly causes spruelike enteropathy, with intestinal villous atrophy as its typical histopathological finding. Interestingly, collagenous and/or lymphocytic gastritis and colitis occur in some patients. We report the case of a 73-year-old Japanese man with a 2-month clinical history of severe diarrhea and weight loss. There were few reports in which spruelike enteropathy and collagenous colitis were both observed and could be followed up. We report a case of a 73-year-old man with a 2-month clinical history of severe diarrhea and weight loss. He had taken olmesartan for hypertension treatment for 5 years. Endoscopic examination with biopsies revealed intestinal villous atrophy and collagenous colitis. Suspecting enteropathy caused by olmesartan, which was discontinued on admission because of hypotension, we continued to stop the drug. Within 3 weeks after olmesartan discontinuation, his clinical symptoms improved. After 3 months, follow-up endoscopy showed improvement of villous atrophy but not of the thickened collagen band of the colon. However, the mucosa normalized after 6 months, histologically confirming that the preexistent pathology was finally resolved. This report presents a case in which spruelike enteropathy and collagenous colitis were both observed and could be followed up. In unexplained cases of diarrhea, medication history should be reconfirmed and this disease should be considered a differential diagnosis.

中文翻译：

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奥美沙坦引起的严重口炎样肠病和胶原性结肠炎

奥美沙坦是一种血管紧张素 II 受体阻滞剂，据报道会引起口炎性腹泻样肠病，其典型的组织病理学表现是肠绒毛萎缩。有趣的是，一些患者会出现胶原性和/或淋巴细胞性胃炎和结肠炎。我们报告一例73岁日本男性，有2个月严重腹泻和体重减轻的临床病史。很少有报道同时观察到口炎性腹泻样肠病和胶原性结肠炎并可进行随访。我们报告一例 73 岁男性病例，有 2 个月严重腹泻和体重减轻的临床病史。他服用奥美沙坦治疗高血压已有5年。内窥镜活检显示肠绒毛萎缩和胶原性结肠炎。怀疑奥美沙坦引起肠病，入院时因低血压停药，继续停药。停用奥美沙坦后3周内，他的临床症状得到改善。3个月后，后续内窥镜检查显示绒毛萎缩有所改善，但结肠增厚的胶原带没有改善。然而，6个月后粘膜恢复正常，组织学证实先前存在的病理学最终得到解决。本报告介绍了一个病例，其中同时观察到口炎性腹泻样肠病和胶原性结肠炎，并且可以进行随访。对于不明原因的腹泻病例，应重新确认用药史，并考虑与本病进行鉴别诊断。