title: Colonic preparation before colonoscopy in constipated and non-constipated patients: a randomized study.
abstract: OBJECTIVE
  To compare the efficacy of different doses of sodium phosphate (NaP) and polyethylenglicol (PEG) alone or with bisacodyl for colonic cleansing in constipated and non-constipated patients.
  
  
  METHODS
  Three hundred and forty-nine patients, older than 18 years old, with low risk for renal damage and who were scheduled for outpatient colonoscopy were randomized to receive one of the following preparations (prep): 90 mL of NaP (prep 1); 45 mL of NaP + 20 mg of bisacodyl (prep 2); 4 L of PEG (prep 3) or 2 L of PEG + 20 mg of bisacodyl (prep 4). Randomization was stratified by constipation. Patients, endoscopists, endoscopists' assistants and data analysts were blinded. A blinding challenge was performed to endoscopist in order to reassure blinding. The primary outcome was the efficacy of colonic cleansing using a previous reported scale. Secondary outcomes were tolerability, compliance, side effects, endoscopist perception about the necessity to repeat the study due to an inadequate colonic preparation and patient overall perceptions.
  
  
  RESULTS
  Information about the primary outcome was obtained from 324 patients (93%). There were no significant differences regarding the preparation quality among different groups in the overall analysis. Compliance was higher in the NaP preparations being even higher in half-dose with bisacodyl: 94% (prep 1), 100% (prep 2), 81% (prep 3) and 87% (prep 4) (2 vs 1, 3 and 4, P < 0.01; 1 vs 3, 4, P < 0.05). The combination of bisacodyl with NaP was associated with insomnia (P = 0.04). In non-constipated patients the preparation quality was also similar between different groups, but endoscopist appraisal about the need to repeat the study was more frequent in the half-dose PEG plus bisacodyl than in whole dose NaP preparation: 11% (prep 4) vs 2% (prep 1) (P < 0.05). Compliance in this group was also higher with the NaP preparations: 95% (prep 1), 100% (prep 2) vs 80% (prep 3) (P < 0.05). Bisacodyl was associated with abdominal pain: 13% (prep 1), 31% (prep 2), 21% (prep 3) and 29% (prep 4), (2, 4 vs 1, 2, P < 0.05). In constipated patients the combination of NaP plus bisacodyl presented higher rates of satisfactory colonic cleansing than whole those PEG: 95% (prep 2) vs 66% (prep 3) (P = 0.03). Preparations containing bisacodyl were not associated with adverse effects in constipated patients.
  
  
  CONCLUSIONS
  In non-constipated patients, compliance is higher with NaP preparations, and bisacodyl is related to adverse effects. In constipated patients NaP plus bisacodyl is the most effective preparation.
authors: Department of Endoscopy, Hospital Alemán, 1118 Buenos Aires, Argentina. lisandro_pereyra@hotmail.com
authors: Lisandro
authors: L
authors: Pereyra
authors: Daniel
authors: D
authors: Cimmino
authors: Carlos
authors: C
authors: González Malla
authors: Mariano
authors: M
authors: Laporte
authors: Nicolás
authors: N
authors: Rotholtz
authors: Carlos
authors: C
authors: Peczan
authors: Sandra
authors: S
authors: Lencinas
authors: Silvia
authors: S
authors: Pedreira
authors: Hugo
authors: H
authors: Catalano
authors: Luis
authors: L
authors: Boerr
mesh_terms: D000368:Aged; D000553:Ambulatory Care; D001118:Argentina; D001726:Bisacodyl / Q000008:administration & dosage* / Q000009:adverse effects; D002400:Cathartics / Q000008:administration & dosage* / Q000009:adverse effects; D016009:Chi-Square Distribution; D003113:Colonoscopy; D003248:Constipation / Q000188:drug therapy* / Q000503:physiopathology; D003672:Defecation / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010710:Phosphates / Q000008:administration & dosage* / Q000009:adverse effects; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000009:adverse effects; D007507:Therapeutic Irrigation / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D002400:Cathartics; D010710:Phosphates; D001726:Bisacodyl; D011092:Polyethylene Glycols; C018279:sodium phosphate
keywords: Bisacodyl constipation; Colonic cleansing; Colonoscopy; Polyethylenglicol; Sodium phosphate
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