The objective of this study was to determine whether patients with Crohn's disease (CD) value the absolute reduction in postoperative recurrence risk attributable to therapy with mesalamine (5-ASA). One hundred subjects evaluated state A (taking 5-ASA; 25% risk of recurrence), state B (not taking 5-ASA; 40% risk of recurrence), and state C (100% risk of recurrence) by rank order, visual analog scale (VAS), and standard gamble (SG). Sixty-five of 91 patients (71%) with completed and usable questionnaires had the same preference order for state A (25% risk), state B (40% risk), and state C (100% risk) on both the VAS and the SG. The mean scores for state A (25% risk), state B (40% risk), and state C (100% risk), respectively, were 67.5, 49.8, and 19.8 on the VAS and 0.977, 0.972, and 0.910 on the SG. Subgroup analyses using stepwise logistic regression showed that risk attitude seemed to be predictive of subjects' preferences for 5-ASA. These results suggest that most subjects seem to value the 15% absolute risk reduction offered by 5-ASA. Furthermore, the SG seems to be a feasible method for measuring utilities for uncertain health states in patients with CD.