The stiffening wires (in two grades of stiffness) used in this study are passed through the biopsy channel of the colonoscope only after its tip has passed the upper end of the descending colon and entered the transverse colon. The device is safe when used as recommended by the manufacturers (and approved by the FDA), and does not appear to increase risk over and above the risk of colonoscopy with the unassisted colonoscope. Although the device clearly improves the stiffness of the colonoscope, there is no research evidence that it actually works in practice, either to improve cecal intubation rate or to decrease procedure time. It is therefore also unclear whether the possible benefit of using the device is achieved if introduced at the first opportunity allowed by the manufacturers or only after difficulty is encountered with the unassisted colonoscope.