SIDE EFFECTS: Dry lips and mouth, minor swelling of the eyelids or lips, crusty skin, nosebleeds, upset stomach, or thinning of hair may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Duration of stomach flu depends on the severity of the attack. The condition may become worse in case of infants, young children and elderly who cannot drink sufficient fluids to compensate for dehydration experienced during the illness. For these people, stomach flu can last for 3 weeks or more.
How long does the flu last? Stomach bugs typically aren't serious, though there are risks of dehydration, WebMD states. Infants and the elderly face greater risks from stomach bugs. Nausea, headaches, fevers and sore muscles are other possible symptoms with a stomach virus, according to Healthline.