PURPOSE: Anal manometry is one of the most commonly used tests to evaluate fecal continence function. Advanced pressure parameters of the tests, such as fatigue rate index (FRI), resting rectoanal pressure gradient (RPG), cough index (CI), and radial asymmetry (RA) are recently devised to make up the inaccuracy of conventional parameters, but without solid verification. The object of this study is to investigate such parameters including conventional ones in incontinent patients compared with those in controls and to determine the significance of each parameter. METHODS: Forty-four patients with anal incontinence and 42 controls were studied. We examined conventional pressure parameters (mean resting pressure [MRP], maximum squeeze pressure [MXSP]) and advanced parameters (RPG, FRI, CI, RA), and compare those parameters with normal controls. Multiple logistic regression analysis and receiver operating characteristic curve analyses were also performed. RESULTS: No difference was detected in demographic factors between the two groups. Basic manometric parameters were significantly different between the two groups (MRP, 31.1+/-20.7 mmHg vs. 41.4+/-18.6 mmHg, P=0.0170; MXSP, 203.1+/-84.3 mmHg vs. 258.5+/-105.9 mmHg, P=0.0086). Among advanced parameters, RPG and FRI were significantly different (2.83+/-1.54 vs. 4.08+/-1.53, P=0.0003; 9+/-21.6 sec vs. 75.6+/-12.1 sec, P=0.0333), but CI and RA were not so different (0.74+/-0.45 vs. 0.61+/-0.33, P=0.1326; 22.7+/-7.0% vs. 21.1+/-7.6%, P=0.3244). Only RPG was significant in multiple logistic regression analysis (P=0.019). Areas under ROC curves were 0.65 for MRP, 0.65 for MXSP, 0.82 for RPG, and 0.73 for FRI. CONCLUSION: Among anal manometric pressure parameters, RPG and FRI as advanced parameters are more accurate than any other parameters in detecting fecal incontinence.