Doctors and scientists have been trying to find the cause of colic for over half a century now. The reports from hundreds of studies of colicky babies are confusing and often contradictory. Some have claimed miracle cures that are hard to believe----babies suddenly got better when parents kept their booties on twenty-four hours a day, or fed them sugar water, or took eyelashes out of their eyes. Most of these studies involved only a few colicky babies and no controls, so we can't know whether the cure really worked or whether the babies got better because they outgrew the problem or their diet or environment changed. More often than not, the results of these studies could not be duplicated when the experiments were run again.

Perhaps the most valuable colic studies have focused on the baby's belly. Throughout history, people have believed that the constantly crying baby was experiencing some kind of abdominal pain; the word colic, in fact, comes from the Greek work kolikos, an adjective derived from kolon meaning the large intestine. We still don't know, however, whether belly pain is always or even usually the cause of crying in the many babies said to suffer from colic. Some parents assume their babies have bellyaches because they draw up their legs when they cry, but babies do this when they hurt in any part of the body. Besides, specialists believe babies can't localize pain--that is, no matter where the hurt originates, babies feel it in the abdominal region. Still, when you can hear your baby's belly gurgling, and when she doesn't calm down until you lay her on your arm and massage her abdomen, you know your baby's crying has to do with her digestion.