Sick Boy

Nicholas has had random bouts of vomiting lately. Last week he randomly woke up at about 11 one night, after having puked all over his bed. After that, there was nothing and he was a bundle of energy the next day. Last night, he threw up all over the floor right before we sat down for dinner. He then proceeded to puke 4 more times in the next 3 hours. He seems fine today...no fever, no lethargy. I know the stomach bug is going around but it seems to hit him very quickly and then disappear. Who knows what's going on?