A couple weeks ago DS had what the doctor thought was Norovirus - sudden onset of throwing up, followed up the next day with diarrhea. After a couple days he seemed to be himself. What I didn't think to mention to our ped is the night before I gave him a couple little tastes of my vanilla ice cream.*

I assumed the ped was most likely right, though the ice cream was in the back of my head and it came up when we MIL over the weekend. She said DH had a lot of stomach issues as a kid and she thinks it may have been a lactose issue back then and she thought the ice cream might really be what caused the vomiting/diarrhea in DS. DH feels he is somewhat lactose intolerant - he eats dairy products like cheese and ice cream, but prefers soy milk for his cereal every day.

DS was breastfed for 6 months (while I ate dairy) and now drinks a standard milk-based formula. He's never seemed to have any issues with either. No blood in his stool, no mucus-y poops, etc.

So, should I ask the ped about a possible lactose intolerance/milk allergy or figure it was the norovirus after all? FYI, DS is 7 months now.

*Yes, some people will think I'm a terrible parent for giving ice cream to a 6 month old. In my defense, he was sick for about 2 months straight and I had to feed him a ton of medicine he hated and now he refuses to eat any food from me. However, he was really interested in the ice cream while I was eating and I though if he had a couple small tastes from me he would see that not everything I tried to feed him was disgusting.