Sudden night waking

Hi,

My wee man, who turns one next week has over the last week suddenly started waking in the night.

He had a nasty tummy bug and slept fine through all of that then when it ended he started waking. He wakes once, somewhere between 11 and 12ish and normally I would ignore but the screaming is intense so I pop in and he is sat sobbing his wee heart out, I lie him down and he looks all sleepy but takes a long long time to resettle, I have started offering a bottle which he downs, he can't need it he is eating and drinking mega amounts at the moment.

Last night it took hours to resettle and I ended up cuddling to sleep.

Very unlike him, he has often stirred in the night but always resettles and even when sick sleeps through, so this is odd, is almost like he is stuck when he finds himself sat up and then can't settle.

other changes he is dropping a nap from 2 to 1 and when at daycare this can mean his total sleep for the day is 30 minutes, I am wondering if this is just not enough.

ideas - just a bit desperate as I am back at work now and the lack of sleep and I then start super early is taking its toll