Sever stomach cramps and nausea, should i be worried or let it p?

this past saturday me and my friend ended up with very painfull stomach aches and we both got the runns for that day. Her pain went away but i still have mine. I havent had the runs since saturday but i feel like im going to puke. I can also eat just fine too but as soon as im done i get really sick, it comes and goes. should i ask my doctor about it or is this a normal virus/bacterial sickness?