Not sleeping through night

Hey ladies and guys,

Looking for help or suggestion. Or even just thoughts here. My LO is consistently waking up every single night 4 hours after he goes to bed like clockwork. He wakes up crying and screaming. And it takes us hours to get him to back sleep. He will fall back to sleep in intervals. He takes a bottle or will fall back to sleep while being rocked or held, but 10 minutes or so later he’s awake crying again. And this goes on an and on for 2-4 hours until he finally falls back to sleep. Only to get up for the day at 7am. We are all sleep deprived. We don’t know what to do and we are at our wits end. Anyone encountering this same problem or something similar? Help!