All patient were evaluated by digital examination, procto-sigmoidoscopy, fistulography and MRI fistulography without contrast media, using a 1.5 Tesla super conducting magnet (Magnetom Symphony MRease VA12 Siemens medical system), (either STIR or SPIR in addition to T1 weighted or T2 weighted sequences). Axial, coronal and sometimes sagittal planes were used. Preoperative assessment of anal sphincter dysfunction was done by conventional manometry using a standard low compliance water perfusions system and eight-channels catheters with pressure transducer connected to 5.5 mm manometric probe with spirally located ports at 0.5cm interval, which measured along the length of the anal canal, as well as inflatable rectal balloon. The protocol of performance is stationary pull through technique with recording the functional length of the anal canal (FL), mean maximum resting pressure in the anal canal (MRP), mean maximum squeeze pressure in the anal canal (MSP). Pressure was recorded using a computerized recording device (MMS ;Holland) which included menu-driven software to aid with data acquisition. Data were analyzed with the use of a complied software package that automatically produced numeric reports and graphs.