Use _revinclude in a FHIR search to retrieve resources that reference the primary search results in the same Bundle

In-depth guide

Steps

1. Identify the referencing resource type and the search parameter that points back to the primary resource type (e.g., Provenance:target to find Provenance resources referencing returned resources)
2. Add _revinclude=[ReferencingType]:[searchParam] to the search query, for example GET [base]/Patient?_id=123&_revinclude=Provenance:target
3. The server returns a searchset Bundle; primary results have entry.search.mode=match and reverse-included resources have entry.search.mode=include
4. Filter entries by search.mode=include and further by resourceType to extract the reverse-included resources
5. Cross-reference each included resource's reference field (e.g., Provenance.target) back to the matched primary resource by id to establish the relationship
6. Chain multiple _revinclude parameters in the same request if multiple referencing resource types are needed; each adds its own set of include-mode entries