Introduction: Olmesartan-induced enteropathy (OIE) is a rare but increasingly recognized cause of chronic diarrhea, often misdiagnosed as celiac disease or infectious colitis. Most cases are mild to moderate and severe presentations requiring ICU-level care are uncommon. We report a case of recurrent hypovolemic shock due to OIE, highlighting the diagnostic challenge and importance of medication review in patients with unexplained gastrointestinal symptoms and hemodynamic instability.
Description: A 63-year-old male with a history of mechanical aortic and mitral valve replacements, atrial flutter, and coronary artery disease presented with profuse diarrhea and vomiting for one week. This was his fourth admission in five months for similar symptoms. On initial admission, he had hypotension requiring vasopressors. Infectious and autoimmune workup, including stool cultures, C. difficile, viral panel, celiac serologies, and colonoscopy with biopsies, was unremarkable. He improved with supportive care and was discharged. Similar presentations recurred on two separate readmissions, both requiring ICU care and vasopressors. Abdominal imaging showed mild enterocolitis, and endocrine workup for secretory diarrhea (gastrin, somatostatin, VIP, calcitonin, 5-HIAA) was negative. On further review, olmesartan had been initiated shortly before his first admission and was being held off at every discharge due to acute kidney injury (AKI). It was discontinued after the third admission, resulting in resolution of symptoms for two months. However, it was restarted as a low-dose combination with hydrochlorothiazide. The medication was permanently discontinued which lead to sustained symptom resolution.
Discussion: Recurrent hypovolemic shock requiring critical care is a severe and underrecognized manifestation of OIE. Diagnosis was delayed due to nonspecific findings and unremarkable histopathology. Symptom recurrence on re-challenge with olmesartan provided diagnostic confirmation. Early recognition and withdrawal of the offending agent is critical to prevent unnecessary testing, hospitalizations, and life-threatening complications. Clinicians should consider OIE in the differential diagnosis of unexplained chronic diarrhea and shock, particularly in patients on angiotensin receptor blockers.
