Background: Nearly 10% of all patients who visit the emergency department report severe abdominal pain. Out of these, almost one-third are not diagnosed accurately. The conventional practice to care for such inpatients involves actively managed observation and repetitive clinical assessments at regular intervals. The aim of this study is to assess the clinical therapeutic effects of opioid analgesia in the treatment of severe abdominal pain in kids and adolescents.Methods: A comprehensive electronic search will be done on Web of Science, EMBASE, PubMed, WanFang database, Chinese National Knowledge Infrastructure, and the Cochrane Library from their establishment to May 2021. The search will identify and retrieve all randomized controlled trials that describe the clinical therapeutic effects of opioid analgesia to treat severe abdominal pain in adolescents and children. Two independent authors will shortlist studies that meet the inclusion criteria, extract data from selected studies, and evaluate the risk associated with bias in the selected articles. We will use RevMan (v: 5.3) to conduct all the data synthesis.Results: This meta-analysis will conduct a high-quality synthesis on present evidence related to the usage of opioid analgesia to treat severe abdominal pain in both kids and adolescents.Conclusion: Our findings will summarize the present evidence and help judge whether opioid analgesia is an effective and safe line of treatment for severe abdominal pain.Ethics and dissemination: This study will use pre-published data, and as such, it does not require ethics approval.OSF registration number: May 29, 2021.osf.io/fp9ym (https://osf.io/fp9ym/).