You are not going to like this answer...No one really knows the cause of Colic.
It is believed to be any one of the following... or perhaps a reason not even listed here!
Your baby may be suffering from one or more of the following:
• immature digestive system
• immature nervous system
• cow's milk protein allergy or intolerance
• over stimulation
• swallowing excess air while feeding or crying
• or has just not taken the transition into the world very well!
And none of these theories have been fully supported by evidence.
Not really the definitive answer you have been searching for, is it?
Please be sure to take your baby to your Health Care Practitioner to confirm that the crying is as a result of Colic and not some other medical condition.
I will however try to give you some practical suggestions on how to get through this very difficult phase in your baby's life!