Compare colonic distension using CT colonography (CTC) and CT with water enema (CTWE) in the same patients.Twenty-seven patients who underwent both CTC and CTWE, considering separately supine (CTC-S) and prone (CTC-P) acquisition of CTC were included. The colon was divided into six segments, performing both a qualitative and quantitative analysis.Adequate distension of sigmoid colon was more frequently achieved with CTC-P and CTWE compared to CTC-S (P.05). CTC-P and CTWE showed better distension of the left colon compared to CTC-S (P.01 and P=.03 regarding sigmoid colon, respectively; P=.01 and P=.03 regarding descending colon, respectively).Computed tomography (CT) studies of the colon should be customized to fulfill the clinical query.