First check all the manholes on the toilet discharge run see if any are blocked if so It's a drain rod job buy or hire and buy duck tape to tape up the rod joints to help prevent them coming undone up the sewer pipe. Turn rods clockwise only to keep them joined.
If it turns out the manholes are clear back to toilet pan bail out [nasty job] pour in a few litres of boiling water so there's onl hot water in pan then mix up some caustic soda a strong mix and pour that in the pan it some times works breaking up what's blocking it. You could try rods by hiring them or buying for the manholes if blocked or call dynorod but they're not cheap.
Bob, October 2010
