The only symptom my daughter had was blood in her stool, other than that she was a happy healthy baby. And yes, until I cut it out completely, there was blood in her stool, but it wasn't consistant in every one. The good news is, that most infants out grow it. My pediatrician told me to wait a until she was a year to try regular cow's milk. My neice was fine by 6 months. My pediatrician did run tests on my daughter. I never thought allergy because she was a "good" baby all other times. It didn't start happening until 3 months, and by then she was eating 7 oz a feeding, and sleeping through the night. She did have gas, but nothing painful.