RESTOREGI Study: Regenerative Endoscopic Stromal Therapy: Outcomes and Risk Factor Evaluation in GI Fistulas

Inclusion Criteria: * Age ≥18 years * Confirmed benign gastrointestinal fistula involving the luminal gastrointestinal tract * Fistula accessible for endoscopic evaluation and treatment * Planned treatment with endoscopic tSVF-EM therapy, with or without adjunctive endoscopic therapies (argon plasma coagulation \[APC\], tract abrasion/curettage, clips, over-the-scope clips \[OTSC\], endoscopic suturing, or stent placement) * Ability and willingness to provide written informed consent * Willingness to comply with scheduled follow-up visits and study assessments Exclusion Criteria: * Perianal fistulas of any aetiology * Inflammatory bowel disease-associated fistulas, including fistulas related to Crohn's disease or ulcerative colitis * Malignancy-related fistulas * Fistulas requiring primary oncologic surgical management * Uncontrolled sepsis or undrained abscess at baseline (patients may become eligible following adequate drainage and clinical stabilisation) * Contraindication to adipose tissue harvest, sedation, anaesthesia, or therapeutic endoscopy * Pregnancy or lactation * Severe coagulopathy not correctable prior to intervention * Inability to provide informed consent * Anticipated inability to complete study follow-up * Participation in another interventional study that may influence fistula healing outcomes