Lemon or more particularly the juice of the lemon is very effective in curing constipation. It clears out your bowels and gets the digestive system moving again. Squeeze out the juice of half lemon and pour it into a glass of warm water. Add some honey or a pinch of salt to it. The first thing you should drink in the morning is the lemon juice solution and make sure that you don’t eat anything before. You can also drink it in the evening. It will relieve you from your tummy ache pretty effectively. So “how to stop constipation fast”, think of having one cup of lemon juice every morning.