Vomiting can occur suddenly. It can happen for a number of reasons - you have eaten stale food; you have some kind of disease; some food has become lodged; you are suffering from food poisoning. Vomiting is the body's reaction to food that it cannot handle. It is nature's way of eliminating a substance that is injurious to the body, so do not attempt to stop the process. Afterwards, try to further clear the system by drinking plenty of water. This will also have the effect of diluting the cause of the illness.
Boil 1 teaspoon of fennel and 1 teaspoon of dill seeds in 3 cups of water. Ensure that the container is enamel or stainless steel and not aluminium. Boil it until 1 cup is left. Filter it and take 1 tablespoon every 2 hours (1 teaspoon for children).
The moment that your body is able to retain something stronger, try a tea that will calm the system such as ginger, camomile, mint or any herbal tea. Boil 1 tablespoon of grated fresh ginger in 3 cups of water until 1 cup remains. Filter the water and drink it slowly. Then eat more alkaline foods, like yoghurt with banana, which will further soothe your system.
It is important to bring up the entire stomach contents, and not to worry about the vomiting - unless you are suffering from bulimia, ulcers or hiatus hernia. If the vomiting continues for longer than 24 hours, seek professional help.