Fewer polyps found toward end of the day

LOS ANGELES, Nov. 5 (UPI) -- U.S. researchers say patients who have colonoscopies later in the day yield fewer polyps.

The study, published in Clinical Gastroenterology and Hepatology, finds early-morning colonoscopies yield more polyps per patient than those done later in the day. The researchers tracked 477 patients receiving colonoscopies during the course of one year at a single VA hospital.

The researchers found an early-morning case -- started at 8:30 a.m. or earlier -- yielded 27 percent more polyps, or 0.19 more overall polyps and 0.17 more premalignant polyps, per patient than cases later in the day. The amount of polyps discovered decreases hour by hour as the day progresses.

However, this translates into less than a quarter polyp per patient, so the risk for individual patients is very low.

"Although individual patient risk is very low, multiplying this effect by thousands of patients across the United States could mean we're missing lots of polyps, some of which might turn into cancer one day," study leader Dr. Brennan Spiegel of the University of California, Los Angeles, said in a statement. "More research needs to be done at a wide range of centers to pinpoint why there's a decrease in the number of polyps found later in the day and to identify ways we might improve outcomes."