Background: Camps for internally displaced people (IDPs) can rapidly spring up as a result of violence – in north-eastern, north-western and north-central Nigeria – in the blink of an eye. IDP camps can be plotted in advance for predictable events like droughts or floods but are rarely so well-prepared for armed violence. WASH services are delayed or absent; cholera thrives. Despite this, most tools used to map the risk of cholera still omit insecurity as a factor in itself. This paper synthesise and appraise evidence on the contribution of WASH, crowding, environmental contamination, and access barriers to cholera risk in displacement settings and generate a risk-stratification framework based on that evidence for insecure camps in Nigeria. Methods: An evidence review was conducted following a systematic search and reported following PRISMA 2020. The literature search was executed in Pub Med, Scopus, and Web of Science along with seven humanitarian grey-literature repositories. Primary studies were critically assessed using the Mixed Methods Appraisal Tool, evidence syntheses using the Joanna Briggs Institute checklist for systematic reviews and research syntheses, and grey literature using the AACODS checklist. Results: After screening 519 search results and grey-literature reports, 18 sources satisfied inclusion criteria: 8 peer-reviewed articles, reviews and preprints, 8 grey-literature reports and 2 normative guidance documents. The evidence for associations between inadequate WASH conditions, crowding and contaminated water and cholera was consistent; primary data from Nigeria was limited and one ecological study showed no association with population density at district level. The majority of Nigerian evidence was from surveillance or humanitarian data collection. Insecurity was referenced in all the sources, but always indirectly via disrupted water supply, crowding or lower cholera surveillance. No source quantified the relationship between insecurity and cholera. The synthesis argues for a new framework based on four domains: WASH environment, crowding, contaminated water and insecurity. The first three are well-established, the fourth is a new and untested hypothesis. Conclusions: This tool provides a transparent platform for decision-makers to prioritize insecure camps for emergency WASH and surveillance. While the parameters are illustrative, the framework needs to be calibrated to camp-level data in Nigeria before operational use. Keywords: cholera, internally displaced persons, WASH, humanitarian access, risk stratification, evidence review, Nigeria