Gripe is caused by muscle spasms and excess acid created when air bubbles form in a baby's tummy. When the air bubbles get trapped in a baby's stomach, the stomach think it is full of food, so acids are produced which would normally break down the food particles. These acids are not needed and can cause irritation. At the same time, because the stomach is full of air bubbles its muscles are unable to relax causing cramps and spasms.
