The folding camping trailer includes a trailer body having partial height sidewalls and end walls, a vertically extendable roof section, an expandable enclosure connecting the sidewalls and end walls to the roof section, and a flush toilet disposed in the trailer body. The toilet includes a waste holding tank for storing sewage waste, a toilet bowl attached to the holding tank, a drain outlet situated on the holding tank for draining the sewage waste and a vent conduit extending from the holding tank to either the roof section or the expandable enclosure connecting the sidewalls and end walls to the roof section.