Hi
You said only one side has water coming out? Toilet bowls have holes under the rim. When you push the handle water flows out the tank down to the bowl where the water comes out these hole under the rim in the toilet bowl forcing the waste water with it to go down the sewer drain. Sometimes these holes become plugged up with junk. You could try pouring some bleach in the tank and flushing it several times to loosen the junk up. If it's still like that after the bleach you may have to manually clean those holes with something like a wire and pick the junk out. If it's really plugged you may have to replace the bowl.
Brad
September 2006