Hi E.,
Let me tell you what worked for me. My son was the same, he would cry everytime he had to go! I tried to help him and that was not working. He would also puke up the formula after drinking it. I told my pediatrician (which by the way is very good) and he didn't agree with me; he told me that it seems a lot to the parent but the child doesn't puke everything and just to give him time. As I said before I disagreed. I bought the Similac with low iron, that worked for about two weeks. My son was 4 months old when I had no other choice after trying other formulas but to change him to regular milk. Yes at 4 months old! I would mix one once of milk with three ounces of water, then 2 ounces of milk with three of water and so on, until he was able to drink just the whole milk. Many may think that it was crazy, but I was going crazy with the constipation and the puking. This was back in 1998, now he is 11yrs old and in perfect health. Go with your guts. You do what the doctor says to do, you go on and try all you can try, but always follow you mother insticts, some times they work better than doctors.