What do these symptoms mean?

For probably a couple weeks, I have not had a normal appetite. The idea of eating anything repulses me and I only eat small things to get rid of hunger pains. I have had runny stool only once or twice a day, but no vomitting and no fever...my stomach gets this gnawing feeling a lot. Hard to explain...what do you think the problem could be? If it helps I'm in my 30's :)