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Effect of Coffee Added to a Polyethylene glycol plus Ascorbic acid Solution for Bowel Preparation prior to Colonoscopy

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Sung Won Jung, In Ho Moh, Hana Yoo, Sung Ill Jang, Su Rin Shin, Jin Bae Kim, Sang Hoon Park, Myung Seok Lee

Gastroenterology and Hepatology, Department of Internal Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea

DOI: http://dx.doi.org/10.15403/jgld.2014.1121.251.cff


Background & Aims: Conventional bowel cleansers for colonoscopy have an unpleasant taste and a large volume of solution must be ingested. Coffee increases bowel motility and has an intense flavor. The addition of coffee to a polyethylene glycol+ascorbic acid solution reduces the volume of the solution to be consumed without reducing efficacy, improves the taste of the solution and enhances patient comfort.

Methods: Outpatients with clinical indication or people who wanted screening for cancer were considered eligible. Control group (PEGAS group) consumed a 1-L solution of polyethylene glycol+ascorbic acid twice. Study group (COF group) consumed 750 mL of coffee+polyethylene glycol+ascorbic acid twice. Bowel cleansing was rated using the Aronchick, Ottawa scale, polyp detection rate and colonoscopic insertion time. Tolerability, acceptability, preference, and adverse events were investigated by questionnaires.

Results: The COF group had non-inferiority in efficacy (non-inferiority margin, -15 %; lower limit of 95 % confidence interval for difference between success rates, – 4.7 % and –8.4 % from both scales, respectively). Polyp detection rates were 0.48 and 0.60, respectively (P=0.067). Colonoscopic insertion times were 323.6±166.8 s and 330.7±243.6 s, respectively (P=0.831). Significant improvement was observed with respect to ease of drinking (P=0.012), taste (P=0.026) and preference (P=0.046) in the COF group. Adverse events occurred in 52.4 % and 60.4 % in the two groups, respectively (P = 0.251).

Conclusion: The addition of coffee to polyethylene glycol+ascorbic acid solution reduces the required volume for bowel preparation without reduced efficacy and enhances patient comfort in coffee-drinkers.

Key words: coffee – bowel preparation– polyethylene glycol – ascorbic acid.

Abbreviations: ASC: ascorbic acid; PEG: polyethylene glycol; AE: adverse event; PP: per protocol; ITT: intention-to-treat; PICO: sodium picosulfate.