Drinking warm water seems to relax the bowel and improve the comfort of colonoscopy, as well as the “completeness” of the procedure, hint findings of a study from Korea.

Colonoscopy involves inserting a thin, flexible scope into the colon to look for cancer or polyps, which are growths that can become cancerous. With colonoscopy, the entire length of the colon can be inspected. It is considered the most sensitive way to screen for colon cancer.

However, “incomplete” colonoscopy examinations - when the full length of the colon can not be examined, for whatever reason - do occur and may lead to some small growths in the colon being missed, Dr. Jae J. Kim, at Sungkyunkwan University School of Medicine in Seoul noted in an email to Reuters Health.

In their study, Kim’s team found that they were able to completely examine more of the large intestine surface (98.4 percent on average) of patients who drank 2 liters (approximately 2 quarts) of warm water just prior to undergoing colonoscopy.

By contrast, colonoscopy reached lesser surface amounts (90.6 and 92.2 percent, respectively) in patients who drank 2 liters of cold water or no water, the researchers report in the American Journal of Gastroenterology.

They compared examination characteristics and pain levels of mostly male patients, about 33 years old and generally of normal weight. Sixty-four each drank warm, cold, or no water along with the standard sodium phosphate colonoscopy prep solution.

Ten to 11 patients in each group had previous abdominal or gynecological surgery. Twenty-one in the warm water group, and 17 each in the cold and no water groups, had irritable bowel syndrome, a chronic condition that causes intermittent bowel irregularities, pain, and bloating.

Generally, patients are sedated during colonoscopy to minimize pain and discomfort, and allow more complete colon examinations, but the volunteers for this study agreed to undergo their scheduled procedures without sedation.

The warm water group as a whole, and particularly those 40 years and younger or with irritable bowel syndrome, reported lesser pain both during colonoscopy and 2 hours later.

This group also required less time for insertion and withdrawal of the examination probe even though their degree of intestinal spasms was similar to those drinking cold or no water.

Kim and colleagues suggest further examinations to determine how drinking warm water affects the bowel and why the apparent benefits persisted well after the examinations.

SOURCE: American Journal of Gastroenterology, December 2009