It's very difficult to judge, Helen. Perhaps most of the carbs he ate today didn't digest and end up as glucose in the bloodstream. Also, his liver could have released some stored glucose. One of my son's tummy bugs was so relentless he was vomiting every 30 minutes or so for a time, even bringing up water and saliva - we had a bag all packed ready to go to hospital, expecting untreatable hypos, when he actually rose a bit and stayed in the 8's - must have been stores from the liver released in response to stress hormones. All you can do is follow the numbers and react accordingly (so glad you've got the pump, so you can actually DO something - some of my son's tummy bugs were on twice-daily mixed insulin, oh God!). Just check BG and blood ketones frequently. If he is continuously hypo with ketones, you need to go to hospital. If he is high with ketones that don't respond to insulin, go to hospital. And if he is dehydrated I would also take him in (pinch up the skin on the back of his hand and let go, it should spring back if he is hydrated, but if not it will stay creased like an old person's skin). But hopefully you will be able to manage things at home and he will get better soon 🙂. You must be shattered too .....