However, once the toilet has leaked at the base, tightening the bolts if they are loose is a temporary fix. You need to pull and reset the toilet with a new wax ring. Since the water that has leaked across the top or bottom of the wax ring causes the wax to loose its ability to seal, tightening it may stop the leaking, but it will probably start again.
As water crosses the wax it deposits on the wax surface evaporated minerals and deposits from the toilet. These products coat the surface of the wax and prevent the wax from bonding to the china.