“Passive-bending colonoscope” significantly improves cecal intubation in difficult cases

Figure 1 Water Navigation Colonoscopy. Red arrows mean buoyancy; Green arrows mean gravity of water; White arrows mean gravity of endoscope. UPD: Endoscope position detecting unit.

Figure 2 Conventional scope stretches the “hairpin” bend and causes pain. Red arrows mean the tension of colonoscope; Brown arrow shows that the tip of colonoscope stretches in the colonic lumen after passing the hairpin bend.

Figure 3 During negotiation of “hairpin” bend of the splenic flexure, “passive- bending colonoscope” does not stretch the bend. Green arrow shows the radius of colonoscope. Passive bending colonoscope has smaller one.

Figure 4 Sigmoid malrotation and loops, malrotation and mesocolon descendens, ascendens of paitents. A: 78 years old female has sigmoid malrotation and loops at splenic flexure; B: 70 years old female has sigmoid malrotation and mesocolon descendens; C: 70 years old male has mesocolon descendens and ascendens.