D.M.
If your son is 'screaming' something is very wrong and he needs something. Babies/Toddlers who wake and put themselves back to sleep without crying or fussing, don't have a need that immediately must be met.
You said 'I have tried to let him fuss it out, but last night he was wide awake until 2:30 and that's when I caved and gave him some motrin to knock him out. I couldn't take it anymore.'
You caved?? I'm confused. You couldn't take it anymore??
I'm trying not to be harsh or to misunderstand what you are asking or what the issue is.
Your son was in pain, and he needed the Motrin and that is not caving. That is meeting your child's need at the time. He is most likely teething and this can be unbearable for a little one. I'm not sure why you think that is caving?!? If he fell asleep after, he was unable to sleep for a reason.
In my opinion, there is never a good reason to let a child cry, let alone scream at night or ever.
He is also probably experiencing growth spurts, seperation anxiety and confusion about why he isn't getting the help he needs from Mommy. It's okay to continue your routines and make sure he sleeps in his bed, but there are ways to maintain continuity while meeting a child's needs.
Before bed, check his gums to make sure they aren't red or inflamed...if they are give him some Mortin so he can make it threw the flare ups without waking.
During growing periods, I give my son a little massage on the legs before bed so he is stretched and comfy. Or if he wakes I rub his legs and talk to him about how it's okay and it will get better. Then, I tell him it's time to go back to bed and he does.
Toddlers need help making these tough transitions, and he is probably not napping becuase he is changing. Do you have a static routine that cues him to nap/bedtime? Our routine no matter where we are or who is caring for my son is the same. This gives him the cue that it's time to rest and even if he doesn't nap we rest on the bed or floor or wherever. It's got to be about making sure that he knows there is a routine and that its going to be the same day after day.
You don't have to look at this as giving in or caving...meet the need and remain consistent with your routine. Please don't let your little one scream or cry, you'll both get more sleep if you tend to his needs at night.
Good Luck.