Characteristics and surgical outcomes of small intestine-rectal fistulas in patients with Crohn's disease.

Purpose: Small intestine-rectal fistulas are a rare and complex complication in Crohn's disease, posing significant diagnostic and management challenges. This study aims to investigate their distinctive features and evaluates surgical outcomes.

Methods: We conducted a retrospective analysis of Crohn's disease patients with small intestine-rectal fistulas who underwent surgery from January 2019 to March 2023. Data on disease characteristics, postoperative quality of life, and functional outcomes were collected.

Results: A total of 92 patients were included, predominantly male (75%). The average time from Crohn's disease diagnosis to small intestine-rectal fistula diagnosis was 5.18 years. Most fistulas originated in the ileum (84.79%), followed by the rectum (9.78%) and both sites (5.43%). Nearly half had perianal lesions (48.91%), with some also having entero-vesical fistulas (22.83%) and entero-vaginal fistulas (1.09%). Significant risk factors for the creation of temporary protective ileostomy included preoperative hemoglobin levels below 100 g/L, albumin levels below 35 g/L, and the presence of perianal disease. Fistulas originating from the rectum and rectal lesions of 3 cm or longer were significant risk factors for rectal resection. No small intestine-rectal fistula recurrence was observed over an average follow-up of 2.35 years. Patients without a permanent sigmoidostomy after small intestine-rectal fistula resection had better stool scores and improved quality of life, especially in emotional and social functioning.

Conclusions: Small intestine-rectal fistulas in Crohn's disease have distinct characteristics. Surgical repair and resection effectively restore intestinal continuity and improve quality of life, particularly when anal function is preserved.