Hello My Stomach Has Been Hurting But Not Nausea. It

Hello My stomach has been hurting but not nausea. It is not a cramping feeling, but a more of a feeling of how your stomach feels after taking a vitamins on an empty stomach. It has been going on for about 3 weeks. Then last Thursday along with the stomach pain I begin to have Diarrhea. This has been accompanied with some lightheadedness