What Causes Loud Noises In Stomach After Intake Of Milk?

My 4 month old has been having loud stomach noises after swallowing some breast milk most mornings. It doesn t happen at any other time of day and he eats 2-3 times at night with no problem. But around 7 am after he swallows, his stomach gurgles, he arches his back, pulls off and cries. I try to burp him, but don t usually get one out. After this happens a few times he won t feed anymore and then needs to be calmed down. We know that he is intolerant of dairy and soy and I ve been on a strict diet for almost a month now. He had specks of blood in his stool, which are looking better. What is causing the stomach pain?