Lemons are loaded with vitamin C and are quite effective in curing digestion problems. They contain digestive juices, which facilitate digestion, thus relieving heartburn, bloating, belching and gastric problems. A glass of lemon juice is often recommended in case of fever and stomach upset. Lemon, when taken with warm water early in the morning, aids in proper digestion. It also removes toxins from the kidney and the digestive system, thus improving immunity and purifying the blood.