Impact of Preoperative Bowel Preparation on Healing Outcomes in FiLaC

NCT07800065 | Not Yet Recruiting

• 1 other identifier: KRC Clinic
• Study Type: observational
• Target: 100
• Locations: 0 countries
• Sites: N/A

Brief Summary

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.

Conditions

Anal Fistula; Fistula in Ano; Laser; Anal Fistula Surgery; Bowel Preparation

Outcome Measures

Primary Outcomes (1)

• Primary outcome Complete clinical healing

  Complete clinical healing is defined as a fully epithelialized external opening with no discharge, inflammation, or other signs of fistula persistence. An independent, blinded colorectal surgeon will assess healing during follow-up. The Perianal Fistula Disease Severity Score (PFDS, 0-4 scale) will also be used for secondary evaluation. Fistulas will be classified as low/simple (superficial, intersphincteric) or high/complex (transsphincteric, suprasphincteric, extrasphincteric) during analysis.

  Three months

Secondary Outcomes (7)

• Secondary Outcome Clinical healing at six months

  Six months

• Clinically confirmed fistula recurrence

  Up to 6 months postoperatively

• Postoperative pain measured by Visual Analog Scale (VAS)

  Day 1, Week 1, Month 1, Month 3

• Change in continence status measured by Wexner Continence Score

  Preoperative and 3 months postoperative

• Incidence of postoperative complications

  Up to 30 days postoperatively

Study Arms (2)

Anal fistula patients receiving bowel preparation before FiLaC

Group A: Anal fistula patients receiving standardised bowel preparation (mechanical bowel preparation with enemas or without) before FiLaC

Procedure: Bowel preparation before fistula laser closure (FiLaC) surgery

Anal fistula patients receiving no bowel preparation before FiLaC

Group B: Anal fistula patients receiving no bowel preparation before FiLaC

Interventions

Bowel preparation before fistula laser closure (FiLaC) surgery PROCEDURE

Standardized bowel preparation will be administered to Group A patients. This involves a clear liquid diet the day prior to surgery. Polyethylene glycol (3 liters) will be initiated at 16:00 PM on the evening before the operation, consumed as 250 mL every 10 minutes, aiming for completion by 21:00 PM. Clear liquid intake is permitted until midnight. If there are particles in the stool on the morning of the operation, a rectal enema will be administered.

Anal fistula patients receiving bowel preparation before FiLaC

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Patients with anal fistula

You may qualify if:

• Age ≥18 years
• Diagnosed cryptoglandular AF (simple or complex)
• Scheduled for FiLaC procedure
• Provided written informed consent

You may not qualify if:

• 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

Sponsors & Collaborators

• Acibadem Kent Hospital: lead

Related Publications (4)

• Sarveazad A, Bahardoust M, Shamseddin J, Yousefifard M. Prevalence of anal fistulas: a systematic review and meta-analysis. Gastroenterol Hepatol Bed Bench. 2022 Winter;15(1):1-8.

  PMID: 35611255 BACKGROUND

• Elfeki H, Shalaby M, Emile SH, Sakr A, Mikael M, Lundby L. A systematic review and meta-analysis of the safety and efficacy of fistula laser closure. Tech Coloproctol. 2020 Apr;24(4):265-274. doi: 10.1007/s10151-020-02165-1. Epub 2020 Feb 17.

  PMID: 32065306 BACKGROUND

• Nordholm-Carstensen A, Perregaard H, Hagen KB, Krarup PM. Fistula Laser Closure (FiLaC) for fistula-in-ano-yet another technique with 50% healing rates? Int J Colorectal Dis. 2021 Sep;36(9):1831-1837. doi: 10.1007/s00384-021-03932-8. Epub 2021 Apr 21.

  PMID: 33881573 BACKGROUND

• Wolicki A, Jager P, Deska T, Senkal M. Sphincter-saving therapy for fistula-in-ano: long-term follow-up after FiLaC(R). Tech Coloproctol. 2021 Feb;25(2):177-184. doi: 10.1007/s10151-020-02332-4. Epub 2020 Aug 31.

  PMID: 32865716 BACKGROUND

MeSH Terms

Conditions

Rectal Fistula

Interventions

Surgical Procedures, Operative

Condition Hierarchy (Ancestors)

Intestinal Fistula; Digestive System Fistula; Digestive System Diseases; Intestinal Diseases; Gastrointestinal Diseases; Rectal Diseases; Fistula; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Semra Demirli Atici, MD

CONTACT

905363624585; smrdemirli@hotmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 6 Months
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: September 17, 2025
• First Posted: September 2, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: September 2, 2026

Record last verified: 2026-08