Sleeve gastrectomy relieves exocrine pancreatic insufficiency in morbidly obese patients: a prospective case-control study - Akpinar, Muhammet; Ozturk, Dogan; Murat, Koza; Aksoy, Evrim; Nazligul, Yasar; Bulus, Hakan (Gastroenterology Review/Przegląd Gastroenterologiczny, 2019)