Toilets, Sinks, Showers, Tubs and Disposals - toilet bowl has little water

Hi I hope someone can help me out with this problem.. im having trouble with my upstairs toilet flushing, i know that the problem is caused by having verylittle water in the bowl what i cant understand is why theres very little water in the bowl when the tank is filling completely, i have poked out the flush holes in the rim and checked the vent on the roof it has suction and can hear the water running when the toilet is flushed leading me to beleive the vent is open. by the way the water level doesnt drop over time after a full flush the tank fills but the bowl doesnt,, all help appreciated
Thanks

The toilet has a built in trap and it will only allow so much water to stay in the bowl. That amount fills the trap and provides the seal to prevent sewer gas from coming into the bathroom. Try taking a bucket of water and slowly pouring it into the bowl. The level of the water should stay the same. The tank opening and letting water stream in is what gives a toilet the "flushing action".You didn't say if this was a new or existing problem. You may end up replacing it to get one that flushes satisfactorily.Good luck and post back.