Stomach flu is not actually related to the "flu" or influenza but is medically known as gastroenteritis. There is no cure for it, but your doctor can help with treatments for some of the side effects. Highly contagious, it is best to ensure you always wash your hands with anti-bacterial hand soap to help prevent those closest to you from also getting stomach flu.
Diarrhea is a common side effect of stomach flu because gastroenteritis is caused by a virus. The type of virus a person with stomach flu might have can be bacterial, causing irritation within the bowels. Drinking plenty of nondairy fluids will help with hydration during the process of the side effect of diarrhea. For a young child, it might be advisable to approach your doctor and ask about dioralyte, which replaces minerals within the body.
Stomach cramps are also a common side effect. The best solution for stomach cramps is to try to go to the bathroom and see if you need to pass a bowel movement. It is best not to try to force yourself, but practice relaxing breathing exercises and allow your bowels to make their own movement. When you feel you cannot make a bowel movement, it is best to relax with slow, deep breaths during the stomach cramps.
Your body would be experiencing more work than normal as it fights the virus. It is best to allow yourself to rest for a few days until you are feeling better and allow your energy to rebuild itself.
To help avoid vomiting, it is advisable to steer clear from dairy products until sufficient time has passed without vomiting, but still take regular sips of fresh water to help clear your system. Seek your doctor's advice.
Depending on the time it can take you to recover, combined with the amount of fluids and possible small meals you have been able to eat, there might be noticeably less water retention and slight weight loss because of your body trying to remove the virus from your system. Once you are feeling better, start eating small and regular meals to help to rebuild what your body needs to return to its healthy form.