abdominal pain and diarrhea often occur together they re most commonly caused by indigestion the stomach flu infections or food poisoning most cases of abdominal pain and diarrhea go away without treatment within four days visit your doctor if you have a fever signs of blood in the stool or can t keep food downrequent constant or severe abdominal pain and diarrhea may indicate a disease or a more serious medical issue common causes of abdominal pain and diarrhea include viral gastroenteritis stomach flu bacterial gastroenteritis food poisoning food allergies pms lactose intolerance