I'm sorry if this has been done before.
Ds1 has just turned 2, and for the past week or so, he's waking at about 2am, crying/screaming his heart out. If we don't go into see him, he'll come to us, and because we have 7wk old ds2, he'll end up coming in bed with us (because we all want some sleep) and goes straight back to sleep. But I know that this is making a rod for our own backs.
At first we thought ds2 was waking him, but as ds2 is now sleeping more at night, its the otherway round.
We haven't changed anything about his routine - still goes to nursery, has meals at the same time etc
Apart from when ds1 was newborn, he's always slept in his own bed, and been a really good sleeper, going from 7/8pm through to 6/7am. This sleep disruption is now really affecting his day, and my happy little boy, is not so happy during the day.