When we are not satisfied with our hair dresser, we see a new one. If you have exhausted your options that your doctor has offered, then seek another opinion. There are a few other options for you as well.
Try a new formula such as Nutragimen which the powder is finely broken down so it is easy to digest. A little more costly, but worth trying. Second, get a second opinion on putting rice cereal, oat cereal in the bottle as recent research is showing this is not going to help "fix" the issue, only masks it or make it worse (as you can tell it is not working for your son). Third, try adding some infant probioitics. If you did not nurse or give him the "golden milk/colostrum" after he was born where all the good bacteria is for their system and help aid in his digestion, then this is an important supplement as he does not have the bacteria to help him digest the dairy in the formula. Here is a nice article about it: http://www.bodyecology.com/07/09/20/introduce_babies_prob...
I also wrote about it in my family health column and you can click on colicky for the research: http://www.examiner.com/x-7158-Chicago-Family-Health-Exam...
Acid reflux/colic/ are all signs of possible food intolerances either to dairy or wheat that may show up later in life. (introducing oats too early can make an infant/child prone to celiac disease, especially before 4m of age).
If you were spitting up after each meal, you wouldn't be happy and would do all you can to resolve it. I use to have acid reflux as an infant, then as an adult until I figured out I had food sensitivities...no more meds, no more pain.
Good Luck,
J. W.
Maternal and Child Health Educator