Internally Displaced Persons (IDPs) in Borno State, Nigeria, live in conditions where access to clean water, adequate sanitation, and hygiene (WASH) is critically inadequate. These WASH deficiencies contribute significantly to disease outbreaks, especially cholera and diarrheal diseases, in the camps. This systematic review and meta-analysis aim to assess the availability, quality, and management of WASH services in IDP camps across Borno State and to identify key challenges, intervention gaps, and response strategies. A systematic search was conducted across PubMed, AJOL, Scopus, ReliefWeb, and grey literature databases for studies published between 2015 and 2024. Out of 1,032 records initially identified, 864 records remained after duplicates were removed. After full-text screening, 38 studies were included in the qualitative synthesis, and 11 met the criteria for meta-analysis. Studies were appraised using the Joanna Briggs Institute (JBI) critical appraisal checklist. The review found widespread contamination of water sources, with over 60% testing positive for E. coli or exceeding WHO bacteriological limits. Sanitation infrastructure in most camps fell below SPHERE standards, with latrine-to-user ratios commonly exceeding 1:50. Open defecation was reported in up to 30% of households. Hygiene practices were poor due to an inadequate supply of soap, safe water containers, and hygiene promotion activities. Flooding and poor coordination among humanitarian actors were significant barriers to sustained WASH delivery. The WASH situation in Borno State IDP camps is critically underdeveloped, placing residents at continued risk of waterborne disease outbreaks. Urgent action is required to improve water quality monitoring, sanitation coverage, and coordinated emergency response.
