Objective: The present study is a randomized controlled trial aiming at comparing the lay open technique with the 
marsupialization technique. It is based on clinical and manometric evaluation of these two techniques in a trial to improve wound healing, reduce anal deformity and decrease incidence of continence disorders after fistulotomy. 
Patients and methods: A randomized controlled study of 52 patients with fistula in-ano. Complex fistulas with multiple 
openings, hoarse-shoe tracts, and suprasphincteric and extrasphincteric fistulas as well as recurrent fistulas were excluded from the study. Miller scoring for continence, anal manometry and saline continence test were performed before operation and 6 weeks and 3 months after surgery. Drawing sealed envelopes did randomization, after fistulotomy was finished. The patients were randomized to have either the wounds left open (LO group) or wound edges marsupialized to the fistula tract by interrupted absorbable sutures (MS group). 
Results: There were no significant differences in the age, sex, and type of fistula, radial distance of the external opening 
from the anal verge and follow-up period between the two groups. Marsupialization of the wound added slightly to the
operative time [10.0 (0.8) versus 7.0 (0.5) min for LO group; p=0.032]. The postoperative hospital stay was similar between the two groups [LO group 2.0(0.5) days; MS group 1.0(0.5) days. Marsupialization of the wound resulted in significantly faster healing [6.0(0.2) versus 8.0(0.5) weeks for LO group; p=0.0001]. This took into account two marsupialization wounds (7.69%), which broke down. At follow-up only one (3.846%) of patients in the MS group complained of incontinence (to liquid stools and flatus) compared with six (23.1%) in the LO group. However, this difference did not reach statistical significance. No recurrence or other complications were encountered in either group. There were no statistical significant differences in the mean resting anal pressure changes at 6 weeks and 3 months after either procedure. There was a significantly greater drop in the maximum anal squeeze pressure at 3 months in the LO group compared with the MS group (p=0.031). There was no difference in these pressure changes at 6 weeks. There was no difference in the anal length change at 6 weeks and 3 months after either procedure. 
Conclusion: Marsupialization of fistulotomy wounds of uncomplicated intersphincteric and trans-sphincteric fistula 
tracts results in more rapid and less deformed wound healing and less continence disorders.