Collagenous gastroenteritis is a rare disease that is known to be associated with the drug olmesartan. an angiotensin II receptor antagonist used to treat hypertension. It is characterized histologically by increased subepithelial collagen deposition with associated inflammation and epithelial injury. Endoscopically. https://www.mamapaisa.com/product-category/shampoo-and-conditioner-set/