An unusual cause of diarrhoea: case report and literature review of olmesartan-associated enteropathy.

Olmesartan is an angiotensin II receptor blocker, approved in 2002 by the Food and Drug Administration for the treatment of hypertension. During chronic therapy with olmesartan, sprue-like enteropathy can occur, being mainly characterised by non-bloody diarrhoea, weight loss and variable degrees of duodenal mucosal damage, which resolved after withdrawal of olmesartan. We hereby report the case of a 77-year-old, poli-treated male patient with a 3-month history of diarrhoea, vomiting and weight loss, associated with severe intestinal villous atrophy and lymphocytic infiltration of gastric and colonic mucosa. After extensive investigations aimed at excluding other possible causes of chronic diarrhoea, a diagnosis of olmesartan-associated enteropathy was made, which was later confirmed by clinical improvement after the discontinuation of the drug. Repeated endoscopy 8 months later showed complete healing of duodenal mucosa with normal villous architecture. Villous atrophy and lymphocytic infiltration of duodenal mucosa are the most described pathologic finding, but several cases of gastric and colonic involvement have also been reported. We, therefore, reviewed the available literature, focussing on the extent of mucosal damage throughout the whole intestine and on its possible causative factors.