IBS stands for Irritable Bowel Syndrome and as the name suggests, is a syndrome rather than a disease. It it very much stress induced by todays lifestyles and can cause you mild to moderate symptoms or severe symptoms.
Symptoms include vague stomachache to severe and crippling stomach pains, normally in your lower stomach, but the pain can be anywhere. You may have diarrhea alternating with constipation or predominantly one or the other.
IBS can also be induced by a bad diet and food intolerances. A lot of IBS suffers also have lactose intolerance and wheat intolerance. You should look at your diet and cut out coffee straight away. This will aggravate your stomach and try to cut out junk food and soda. Also try to reduce your stress levels as much as possible and if your IBS is mostly stress induced, then reducing this will help your stomach a lot.
This is just an overview, but go and do some research and reading up. There is lots of information out there on IBS.