When the combination of vomiting and diarrhoea strike at the same time, you probably have what is commonly known as the stomach flu or gastroenteritis. Brought on by an inflammation of the digestive tract, stomach flu can be caused by a virus, bacteria or by the accidental ingestion of toxins. The only true cure is time, as the illness often runs its course in 48 to 72 hours; however, there are a number of things you can do to help alleviate your symptoms.
Pass up drinks and don't eat anything for the first two hours after vomiting. This will allow the stomach and intestines to rest and recover. After two hours, take small sips of clear liquids such as water, apple juice, lemon-lime soda, ginger ale, sports drinks or a special rehydration fluid such as Pedialyte. If your choose juice, soda or sports drinks, dilute them by half for the first few hours as the sudden influx of sugar can aggravate diarrhoea.
Avoid solid foods until you can safely consume eight ounces of fluid. Then nibble on simple carbohydrates that are easy to digest such as saltine crackers, toast, bananas, rice or broth. It is best to remain on this type of bland diet for 24 to 48 hours, or until the worst of the illness has passed.
Take a dose of motion sickness medication if you have it on hand. It can relieve your upset stomach. Additionally, it tends to make people sleepy, which can be beneficial if you're having trouble resting because you don't feel well.
Stay away from dairy foods, highly acidic foods such as orange juice or coffee, sugary sweets, spicy foods, fried foods or alcoholic beverages until the illness has run its course. These items tend to irritate the digestive tract and will undermine your body's recovery efforts.
Monitor your symptoms. If the vomiting has not improved after 24 hours, if you see no improvement in the diarrhoea after three days of self-care or if at any point your symptoms get worse rather than better, you should consider seeking professional medical advice.
If your diarrhoea becomes bloody, if you vomit more than 10 times in 24 hours, if you develop a fever greater than 39.4 degrees Celsius, if you're experiencing severe abdominal cramping in addition to fever, vomiting and diarrhoea, or if you are ill and have recently returned to your home after touring a foreign country, please seek emergency medical care immediately.