OBJECTIVE: This study aims to systematically search, screen, evaluate, and summarize the best evidence related to the dietary management of patients with high-output ileostomy, providing an evidence-based reference for the dietary management tailored to this specific demographic. METHODS: A comprehensive search was conducted across multiple databases, including BMJ best practice, Up to Date, Guidelines International Network, Medlive, National Institute for Health and Care Excellence, Scottish Intercollegiate Guidelines Network, Registered Nurses Association of Ontario, JBI, Cochrane Library, PubMed, CNKI, Wanfang, and VIP databases. Additional searches included websites of professional organizations such as the European Society for Clinical Nutrition and Metabolism, Chinese Society for Parenteral and Enteral Nutrition, American Society for Parenteral and Enteral Nutrition, World Council of Enterostomal Therapists, United Ostomy Associations of America, and International Ostomy Association. Two researchers independently evaluated the quality of the included literature and extracted and summarized the evidence. RESULTS: Eighteen articles were included: 2 clinical decision documents, 5 guidelines, 3 expert consensus statements, 6 expert opinions, and 2 evidence summaries. Thirty pieces of evidence were synthesized, covering nutritional risk screening, dietary guidance, dietary behavior guidance, health education, and follow-up care. CONCLUSION: The summarized best evidence is scientific and comprehensive, offering an evidence-based guide for healthcare professionals managing the dietary needs of patients with high-output ileostomy.