Toddler screamed for 3 hours last night. Advice please!

[Jet888]

Help me...
2.9 year old always been great sleeper until last few weeks....
Can still get him down at 7 as usual, but he has then been waking few hours later and crying. The crying turns into screaming, shouting and screeching and lasts for hours. We tried ignoring for a while to see if he'd settle but he wouldn't. We tried going in and resettling at increasing intervals, controlled crying style, but that seemed to make no difference. I tried the shuffle method (moving closer towards door gradually) but after 45 minutes he still starts screaming if he realises im not in the room. He seriously has been crying/screaming for 3 hours most nights and it's killing me.
I don't want to instill habits I don't want to continue like sleeping in his room or co-sleeping but need to know if anyone has had same problem and fixed it. Or did it just end as quickly as it suddenly started? He is warm enough, had calpol at times in case of teeth, not seeming to have nightmares etc.
Sorry for long post, I'm desperate

A couple of my kids had night terrors starting at this age. But if it’s night terrors then they scream and cry without really being conscious/awake. So they can’t answer questions or anything like that. Is your DS awake and communicating or not?

When we had this with toddler DS it was worms. If it’s proper screaming not just mucking about and wanting attention I would assume it’s real discomfort or fear.

Just bring him into bed with you and sook up all the cuddles he'll be 16 before you know it.
Who cares about bad bed habits he's your baby enjoy him while it lasts

My daughter had ear infections and always started with night waking. They soon became obvious in the daytime in her case though.
I was also going to suggest a worm inspection. Look around butt with a torch at night.

Thanks all. It's not pain screaming, it's definitely attention screaming for want of a better description. More of a loud yell than a scream id say