The relationship between symptoms and manometric data was studied in incontinent patients. Conventional anal manometry, the rectal saline infusion test and the balloon-retaining test were performed in 27 control subjects (M:8, F:19; mean age: 47 yr) and in 40 incontinent patients (M:5, F:35; mean age: 49 yr). The correlation coefficient between the clinical degree of continence/incontinence and the maximum anal basal tone, squeeze pressure and the pressure increment during squeeze was -0.74, -0.74 and -0.57, respectively. Discriminatory values of > 40 mmHg for maximum basal pressure and > 92 mmHg for squeeze pressure could identify continent patients with 96%, and incontinent patients with 88% accuracy. The uncontrollable evacuation of a balloon, progressively filled with water at 60 ml/min, before the maximum tolerable sensation level was reached, was related to the degree of clinical incontinence. Also the maximum retained volume and the interval between the first sensation volume and the maximum retained volume ("perceived rectal capacity") were related to the clinical symptoms: r = -0.72 and -0.71, respectively. The balloon-retaining test proved to be superior to the rectal saline infusion test for the determination of the severity of incontinence. The saline infusion test, however, was found to be more adequate to identify minor defects of continence. Thus, the manometric assessment of anorectal continence should consist of routine anal manometry, the rectal saline infusion test and the balloon-retaining test. Some important clinical implications are discussed.