Formula would be the last resort. I so want to give you an award for sticking in there and continuing to work on this. Doctors. Just amazing that he thinks it is your breastmilk and wants you to switch to formula - just shaking my head here.
The first thing you have to do is no vaccines as your baby is not well and compromising the immune system at this time could have terrible consequences. The breastmilk is the best form of nutrition for him so keep at it. Elimination of certain foods is good. With my daughter it was soy and eggs that were the major culprits and then dairy, gluten. Did you know that those ingredients are found in vaccines?
Have you incorporated probiotics and omega 3s into your diet so that your son can benefit from them? My son had sphincter stenosis which caused him to have some spit up and be in pain from not being to have bowel movements properly and they were trying to tell me he was just colicky. Changed doctors and the one that we changed to knew exactly what was wrong with him with just my telling of the symptoms.
Please make sure YOU have done the research on vaccinations for YOUR child. The AAP recommended schedule of shots for children is too many, too soon. Here are sites and books that I always recommend for people to start their research:
Healing the New Childhood Epidemics: Autism, ADHD, Asthma, and Allergies: The Groundbreaking Program for the 4-A Disorders, by Dr. Kenneth Bock
The Vaccine Book, by Dr. Robert Sears
What Your Doctor May Not Tell You About Childhood Vaccinations, by Dr. Stephanie Cave
Evidence of Harm, by David Kirby
www.909shot.com
www.tacanow.org
www.generationrescue.com