title: A randomized controlled trial comparing a low-residue diet versus clear liquids for colonoscopy preparation: impact on tolerance, procedure time, and adenoma detection rate.
abstract: OBJECTIVE
  To achieve an excellent bowel preparation, it is routine to require a clear liquid diet on the day before the procedure. Unfortunately, this dietary modification may be poorly tolerated. We examine whether a change in precolonoscopy dietary restriction can lead to better patient tolerance without compromising examination quality.
  
  
  METHODS
  This is a prospective, blinded, randomized controlled trial of patients undergoing screening or surveillance colonoscopy. The primary objective measures the effect of dietary modification on bowel prep quality. Secondary endpoints include polyp detection, patient tolerance, withdrawal time, and patient acceptance. A total of 200 patients were randomized to either (a) a low-residue diet for breakfast and lunch the day before the procedure or (b) clear liquids all day before the procedure. All patients underwent an identical low-volume sodium sulfate split prep. Bowel prep quality was scored using the Boston Bowel Preparation Scale (BBPS). A t test with TOST was used for noninferiority. Secondary endpoints were compared using χ analysis.
  
  
  RESULTS
  Overall, 96.5% of patients had a good or excellent bowel prep (BBPS=6, 7, 8, or 9). LRD prep quality was noninferior to CLD prep quality (LRD 7.8 vs. CLD 8.1). Polyp detection rates were similar (68% vs. 65.4%, P=0.6899). Patient tolerance and acceptance did not differ. Withdrawal times were equivalent between both groups (16.2 vs. 16.5 min, P=NS).
  
  
  CONCLUSIONS
  Patients allowed to have a limited low-residue diet before colonoscopy achieve a bowel prep quality that is noninferior to patients on a strict clear liquid diet limitation. Furthermore, polyp detection rates, patient tolerance, and patient acceptance were similar between the 2 groups.
authors.affiliation: *Department of Gastroenterology, Park Nicollet Clinic †Park Nicollet Institute, St Louis Park ‡Department of Internal Medicine, Division of Gastroenterology, University of Minnesota Medical School, Minneapolis, MN.
authors.forename: David R
authors.initials: DR
authors.lastname: Stolpman
authors.forename: Craig A
authors.initials: CA
authors.lastname: Solem
authors.forename: Dianna
authors.initials: D
authors.lastname: Eastlick
authors.forename: Susan
authors.initials: S
authors.lastname: Adlis
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Shaw
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D001628:Beverages / Q000009:adverse effects; D002400:Cathartics / Q000008:administration & dosage; D016009:Chi-Square Distribution; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy / Q000009:adverse effects; D003116:Color; D004032:Diet / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D010349:Patient Compliance; D017060:Patient Satisfaction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D002400:Cathartics