My son is 2 1/2 and started having the same issues. Once we moved him from the crib to his big boy bed and new room, we had kept the rocking chair in there with him. He'd always had his books read to him in the chair so we kept the tradition. He did great at first. Not a peep from his room all night! We were so happy! But things soon changed. He was waking up 2,3,4 times a night wanting me to rock him. I'd do it until he was asleep and then put him gently back to bed. As soon as he realized he was in his bed and not rocking in the chair with me, he was up again. I finally realized I needed to take the rocking chair out of his room and read to him in his bed. That worked perfectly. Until...he wanted us to lay with him ALL NIGHT. We started off laying with him until he fell asleep. But he just kept getting up like before with the rocking chair. So we decided to read books with him in his bed, lay with him for only a couple of minutes after, and then tell him good night. He'd go right to his door (it has a gate in front of it)and yell for me, "MAAAAMAAAAAA! MAAAAMAAAAA!" I would go into his room (only once in a night), tuck him in again and softly tell him that was the last time I would come in there. I told him he was ok and I was right there if he needed me. I'd tell him to TRY and fall asleep. He would call for me again a few more times but I would only say from the stairs to get back in bed and try to fall asleep. Each time I reassured him he was ok. This lasted about 3-4 days. Then, he would just call for me from his bed and not get out. I'd come up to his door and tell him to close his eyes and TRY to fall asleep (I wouldn't come inside his room). I'd tell him that he's ok and I'm right here. Well, it worked. The only time I actually go into his room to comfort him is if he really is scared. Other than that, I simply ask him to close his eyes and TRY to fall asleep. I always reassure him that "I'm right here." He's been sleeping through the night for 6 months without waking up AT ALL.
I hope this helps. It took some time (about a week) but he now feels safe and comfortable by himself in his own bed, knowing we're just down the hall to protect him.