Bloody Stool
Stomach flu might affect your digestive system and cause some issues with your bowel movements. One of the most common complications is a bloody or dark stool. Keep in mind that the darker the stool, the farther inside the body the infection occurs. In other words, light blood suggests that it comes from the anus, while dark blood indicates that the stool has been moved all the way from your intestine or colon. In most cases, this is a severe symptom and requires medical treatment from a doctor to prevent further damages to your stomach. [8]
