Most tummy aches are caused by hyperactive bowel movements, the presence of inflammation, and imbalance of flora, which are also the main factors that cause diarrhea. Tummy aches and diarrhea mostly coexist and are mainly caused by the presence of diseases in the intestinal system. In some people, stomach pain is caused by intestinal dysfunction and hyper-peristalsis, which is accompanied by diarrhea because the peristalsis is too fast and the contents of the intestine are also expelled rapidly during the peristalsis. Inflammatory factors are released when there is inflammation in the intestinal mucosa, causing pain in the stomach due to irritation of the smooth muscle of the intestinal wall. The metabolic products of harmful bacteria in overproduction can cause abdominal pain due to irritation of the intestinal wall, and harmful bacteria can also stimulate intestinal peristalsis and affect intestinal absorption, thus triggering diarrhea.