The researchers performed a retrospective review of 185 patients undergoing VC at two separate medical centers over three months. Half underwent standard overnight preps and half had the two-hour prep. All the two-hour preps were performed on patients with same-day incomplete colonoscopy. Both groups got the same 30 mL of diatrizoate meglumine and diatrizoate sodium solution.
Dr. Kristopher Daley and colleagues from Providence Hospital and Boston Medical Center looked at six colonic segments separately. They found that the two-hour prep did as well as the overnight prep in cleansing the proximal colon, though the overnight prep still had advantages in the distal colon, where most polyps are found.
"The two-hour prep is best reserved for patients with same-day incomplete colonoscopies," presenter Daley told AuntMinnie.com. "Any patient who is scheduled ahead of time as an outpatient gets the overnight prep, because you do need to tag the distal colon effectively. However, in the majority of patients with incomplete colonoscopies, the proximal colon is the area that is typically not visualized during the exam."
The two-hour prep was significantly more effective at opacifying the proximal segments, making it a good choice after failed colonoscopy, Daley said. On the other hand, patients who present primarily for screening VC rather than optical colonoscopy "may benefit from a longer overnight prep as polyps are statistically more common in the distal colon," he said.
