Last Week, After A Fairly Stressful Day, I Developed A

Last week, after a fairly stressful day, I developed a soreness to my lower right abdominal area and diahrea.
Over the last few days, the soreness seems to have gotten a little worse. It hurts mostly when I press on the area. Diahrea has gotten to the point where I need to use the bathroom several times per day. Imodium helps temporarily. Urine is a little darker than normal which I think indicates dehydration which is consistent with the fact that my mouth has been pretty dry the last few days. Any thoughts?