Appropriate colonic preparation is essential for early detection of colonic neoplastic lesions. Objective: To describe the clinical response of the two colonic preparations currently used in the digestive endoscopy service of the Hospital Universitario Hernando Moncaleano Perdomo at Neiva, Colombia in outpatients. Methods: A descriptive study carried out in a case series, by reviewing clinical records of patients who underwent ambulatory colonoscopy at the endoscopic unit of the hospital. Data were collected from September 3, 2014 to 3 of September 2015. Half patients received standard dose of polyethylene glycol (group 1) and the other received polyethylene glycol + bisacodyl (group 2). We collected sociodemographic variables, preparation colonic scale of the Boston University (Boston Scale), adverse reactions and colonoscopic findings. Results: A high proportion of patients have good colonic preparation according Boston Scale with both schemes without statistically significant differences between groups. An important proportion of adverse reactions were found. Conclusion: Both the preparation of half of Polyethylene Glycol plus Bisacodyl 20mg and the standard Polyethylene Glycol had an excellent performance in the preparation of the colon of outpatients.