Background: An external straightener for colonoscopy which enables proper compression of the abdomen during the entire examination has been developed. Methods: Beginning January 1, 1997, patients undergoing outpatient colonoscopy were subjected to either manual abdominal compression or compression with an external straightener. Two hundred patients were divided into two groups of 100 patients each: group A (colonoscopy using traditional methods; 38 men, 62 women, mean age 59.6 years, range 18 to 80) and group B (colonoscopy with the help of the external straightener; 40 men, 60 women, mean age 59.8 years, range 16 to 75). Fifteen minutes after the examination, each patient completed a form that assessed the degree of pain during the procedure (no pain, mild, moderate, severe). Results: The ileocecal valve was reached in 89 cases in group A and 94 cases in group B. The average time required to reach the valve was 9.34 ± 4 minutes (range 4 to 25) in group A and 6.97 ± 3.37 minutes (range 2 to 21) in group B (p < 0.001). With regard to the degree of pain, the results for groups A and B were, respectively: no pain = 25% and 40%, mild = 29% and 34%, moderate = 30% and 20%, severe = 16% and 6% (p < 0.001). Conclusions: The external straightener reduced examination time and decreased the degree of patient pain compared with traditional methods.