Impact of Preoperative Bowel Preparation on Healing Outcomes in FiLaC

Background: Fistula tract laser closure (FiLaC) has emerged as a sphincter-preserving treatment for anal fistula (AF). However, the optimal role of preoperative bowel preparation (BP) in enhancing postoperative outcomes remains contentious. While some surgeons recommend enemas to empty the rectum, others ignore BP altogether due to concerns about possible contamination from enemas. Current guidelines suggest that the decision to perform BP is at the surgeon's discretion, as it is not definitively linked to healing rates. Objective: This prospective, non-randomized observational cohort study aims to evaluate whether preoperative bowel preparation significantly impacts primary healing rates following FiLaC in patients with anal fistula. Methods: One hundred consecutive patients undergoing FiLaC will be prospectively enrolled and stratified into two cohorts: Group A (BP) and Group B (no BP). Anal fistulas will be classified by Parks classification. The primary outcome is complete clinical healing at three months, defined by the absence of discharge, an epithelialized external opening, and no recurrence. Secondary outcomes include six-month healing rates, recurrence, postoperative pain, quality of life, Wexner continence scores, and complication rates. Multivariate logistic regression will be employed to control for potential confounders, including smoking status, prior seton use, and fistula complexity. Discussion: This study aims to fill the evidence gap regarding the benefits of preoperative BP in FiLaC procedures, improving perioperative protocols to optimize healing outcomes while reducing unnecessary interventions. The findings will provide clinicians with evidence-based guidance on BP strategies.

Inclusion Criteria: * Age ≥18 years * Diagnosed cryptoglandular AF (simple or complex) * Scheduled for FiLaC procedure * Provided written informed consent Exclusion Criteria: * Fistula associated with Crohn's disease, tuberculosis, or malignancy * Signs of inflammation (presence of abscess) * Anovaginal fistulas * History of pelvic radiotherapy * Incomplete data or loss to follow-up prior to 6 months