My 3.5 month old boy has been projectile vomiting about once a day for the past 6 days. He has also had diarrhea/blowouts or at least much looser stools than normal. We've spoken to the doctor a few times and they say as long s he's not dehydrated or running a fever (which he's not), that we should let it run it's course and that it may be a bug. I'm worried as he normally eats six 6oz bottles of formula a day, and lately hes been only eating around 24 oz (minus whatever he pukes). Overall, he seems happy, but I'm so nervous being a first time mom. The only change in his diet is that we switched him from Target Sensitive Formula to the Walmart brand about 3 weeks ago. he's a good sized boy and never has issues finishing a bottle where today he refused two. We did try switching him to Soy today, as both my brother and I were on soy as babies and I thought it could be an issue with formula. Could it be a milk issue, sickness, teething, other???
I'm certainly no expert, especially on your baby, but 36 oz a day of 6oz at a time seems a little high for a 3.5 month old. According to the AAP, 32 oz should be the max but I know all babies are different. I only mention this because lots of spitting up can also be a sign of overfeeding. When does he vomit/spit up during the day?
My little guy had about 2 weeks of projectile vomiting when he was a little over a month old. He was breastfed, and I think we determined that he was eating a little too much. I know it's a little different with formula, but if their bellies get to full, I think it all comes out... not just the extra. I also became a much more determined burper during this time - maybe he needs more breaks to burp?
He's a good sized baby for his age, tall, but not overweight. 99% . Doctor stated the 36 oz was just fine as he's about 17 lbs. He will usually (but not always) spit up just a little after a feeding. Sometimes if he gets over excited and starts dancing/shaking around Or if he doesnt get a good burp. I'm not too concerned with the spit-up as it's not a tremendous amount. it's the sudden change and projectile vomit and diarrhea that concern me.
My boys would spit up and/or get diarrhea when teething but he seems a little young for that, but it's a possibility. I would give the new formula sometime before switching again, it can take a bit for them to adjust. My LO projectile vomits about once a week but I don't know why, I'm not worried she's gaining weight and is happy. If your pediatrician isn't worried then you should try and not worry. I know it's hard, especially with the first but it might just be a phase. Good luck.
Re: 3.5 month old and projectile vomit!
https://www.whattoexpect.com/first-year/how-much-formula-does-your-baby-need
Good luck mama!