My baby boy is 3 months today. Was exclusively BF until 4 weeks ago when I started giving formula during the day while I m at work. He gets 2-3 bottles a day, and the rest he still nurses. Last Thurs night he vomited...on Friday he did as well, after 2 bottles. Saturday after 1 bottle he vomited again, so I continued to nurse the rest of the day because he had/has no fever and was acting fine after nursing. We thought something was wrong with formula, so we returned it and got a new kind. Sunday he vomited after formula twice. Monday (yesterday) he did not vomit after formula, but vomited after nursing. I took him to urgent care last night, and then he get blood/ urine tests at hospital. Dr. said maybe pyloric stenosis . Today he didn t vomit until 2 hours after formula. Went back to Dr...lab results were normal except slightly elevated lymphocytes. She said maybe a virus...still no fever and otherwise fine. She said to do pedialyte all night and bring him back tomorrow. I just nursed him a little (he s starving), and he had some spit up, but nothing major...yet. Any ideas what this could be? The dr today said she d probably have an upper GI ultrasound done tomorrow. He s starving though. I can t just give him pedialyte!! Any help is appreciated!!