Sick again, but better now

DS2 was sick again last weekend. Thursday night he threw up twice, then 3 more times Friday morning. Two weeks prior he got sent home from daycare because he threw up there but didn't ever do it at home. In the month of August, everyone in the family has had a day of "stomach flu", one end or the other. :-( Last week DS2 had been somewhat constipated, too, but that all came out Friday and then it turned slightly like diarrhea. While he was sick I fed him only breast milk, so then his stools finally turned back into "breastmilk poop". Late Saturday I gave him a little cereal, and I also gave him some on Sunday. He's back to normal now, as far as I can tell.