Is it feasible to reach the bypassed stomach after Roux-en-Y gastric bypass for morbid obesity ?: the use of the double-ballon enteroscope - Sakai, P.; Kuga, R.; Safatle-Ribeiro, A. V.; Faintuch, Joel; Gama-Rodrigues, J. J.; Ishida, R. K.; Fruya Junior, C. K.; Yamammoto, H.; Ishioka, S. (Endoscopy, 2005)