A diet of white foods the day before a colonoscopy does not negatively impact colonoscopy performance and is preferred by patients over the usually recommended clear-fluid diet, Melbourne gastroenterologists report.

Joshua Butt and colleagues from The Alfred Hospital in Melbourne randomised patients who were due to undergo a colonoscopy to a diet of white coloured foods or a clear-fluid diet.

All patients received a 2-liter polyethylene glycol lavage solution with ascorbate, sodium sulfate, and electrolytes, the day before for morning procedures and as a split dose for afternoon procedures.

The researchers found that bowel preparation was successful in 91% of patients on the clear-fluid diet and 84% on the white diet, a difference which was within the pre-defined limits for non-inferiority.

However there was a higher bowel preparation success rate associated with the split-dose regimen versus the day-before regimen (96 versus 80 percent).

Although the study wasn’t powered to detect differences between the regimens the finding was important in an Australian context where day before dosing is anecdotally still common.

“The White Diet was preferred and better tolerated by patients without detriment to the success of bowel preparation or colonoscopy performance, especially with the split-dose regimen,” the authors concluded in the study which was published in the Journal of Gastroenterology and Hepatology.

White foods included foods such as white bread, white rice, cheese, milk and even lolly milk bottles.