Comparison of two schemes of small bowel preparation for capsule endoscopy with polyethylene glycol: a prospective, randomized single-blind study - Kantianis, Alexandros; Karagiannis, Stephanos; Liatsos, Christos; Galanis, Petros; Psilopoulos, Dimitrios; Tenta, Roxane; Kalantzis, Nikolaos; Mavrogiannis, Christos (European journal of gastroenterology & hepatology, 2009)