How do I find a deceased colonist in RimWorld?
Solution 1:
Instead of looking for the corpse, create a grave and order them to be buried. As long as the corpse isn't destroyed (in which case the thought should go away) or inaccessible, someone will bury it.
If you can remember their name, this can be done either by assigning the grave to the colonist. If not, set an empty grave to only access colonist bodies and wait.
Burying is done by Haulers, so you might use the "work" tab to ensure someone is doing a lot of hauling.