Intubation by looping. A. The sigmoidoscope is advanced to the distal sigmoid. B. Counterclockwise torquing during further advancement loops the proximal sigmoid in front of the distal sigmoid. C. The looped sigmoid flattens the angle at the distal-descen
Intubation by elongation. A. The sigmoidoscope is advanced to the proximal sigmoid. B. Severe tip deflection prevents further advancement resulting in sigmoid elongation. C. Clockwise torquing and shaft withdrawal accordionizes the sigmoid.