UNDERWATER ENDOSCOPIC RESECTION FOR COLONIC LESIONS IN DIFFICULT AND CHALLENGING SITUATIONS. MULTICENTER – PRELIMINARY RESULTS - Uchima, H; Rodriguez-Sanchez, J; Marin, JC; Torrealba, L; Sánchez-Alonso, M; Busquets, D; Turro, R; Albert, M; Mata Bilbao, A; Espinos, JC (Endoscopy, 2019)