How is diarrhea associated with headaches? What is IBS? IBS is an intestinal disorder that causes pain in the stomach, gas, diarrhea and constipation. Regular adjustments can help regulate your bowel movements and relieve symptoms from IBS. Watch the video below to see how diarrhea is associated with headaches and how Dr. Mosier can help! Continue watching to the end to see a remedy that you can do at home!