Comparison of reduced volume Versus four liters sulfate-free electrolyte lavage solutions for colonoscopy colon cleansing

OBJECTIVE: In an attempt to improve patient tolerance for colonoscopy cleansing, a reduced volume lavage regimen with 2 L sulfate-free electrolyte lavage solution (SF-ELS, Nu-LYTELY, Braintree Laboratories, Braintree, MA) plus 20 mg p.o. bisacodyl (Half Lytely, Braintree Laboratories) was compared with standard 4 L SF-ELS lavage for safety and efficacy. METHODS: At two centers, 200 patients undergoing colonoscopy for routine indications were randomized to receive the reduced volume or standard 4 L method. The day before scheduled colonoscopy, study subjects were allowed a normal breakfast and clear liquids for lunch and dinner. Those randomized to receive the reduced volume method received four 5-mg bisacodyl tablets p.o. at noon. Six hours later, they received 2 L SF-ELS given as 10 oz every 10 min. Subjects randomized to receive 4 L SF-ELS also drank their solution at 6:00 PM in a similar fashion. Colonoscopists, unaware as to the randomized preparation received, rated efficacy of cleansing. Patient tolerance and various hematological and biochemical parameters were assessed. RESULTS: Physician assessment of colon cleansing showed no differences between those patients randomized to receive reduced volume (n = 93) or 4 L (n = 93) SF-ELS cleansing (p = 0.16). There was a profound reduction in preparation side effects. The reduced volume preparation had less fullness (p < 0.01), nausea (p < 0.01), vomiting (p = 0.01), and overall discomfort (p < 0.01). There were no clinically significant changes in hematology or blood chemistry associated with either preparation. CONCLUSIONS: Reduced volume preparation with 2 L SF-ELS and bisacodyl is safe and effective. Clinical symptoms from the reduced volume preparation are significantly reduced compared with traditional 4 L gut lavage.