Objective: The study is randomized controlled trial aiming at comparing the outcome of surgery for high perianal fistula 
in 2 groups of patients. Depending on preoperative assessment either traditionally by fistulography in group A or by MRI in group B. Both groups followed up clinically and by manometry. This study is a trial to improve the outcome of surgery for the high perianal fistula. 
Patients and methods: This study included 2 groups of patients each group includes 12 patients with high perianal 
fistula, non recurrent evaluated in group A by clinical examination, fistulography careful propping under anesthesia, 
occasional injection of methylene blue to define internal opening. In group B. all patients underwent preoperative contrast enhanced Magnetic resonance image (MRI) of the perianal region. Both groups followed up clinically to assess wound healing, cure rate and by manometry to assess the patient continence. 
Results: There were prominent superiority for the MRI in the assessment of primary track, secondary track, Horseshoe 
track, internal opening, and significant superiority in detection of Abscess (6patients) in group B versus (3patients) in groupA. RAP dropped in both group at 10 weeks postoperative (70.04 ± 598) in group A and 74.4 ± 7.5 in group B. at 24 weeks slight improvement in both group but more in gpB. MSP dropped at 10 weeks post operative in both groups more in gp A. By 24 weeks improvement of MSP was noticed specially in gpB. No significant difference between operative time, hospital stay in both groups but incontinence recorded as 25% in gpA and 16.7% in group B and recurrence recorded in 2 patients in gpA and one patient in group B. 
Conclusion: Good assessment of high perianal fistula preoperative resulted in improvement of the outcome of the fistula 
surgery.