Hi Megan,
As a sleep consultant for infants and preschoolers, I often get questions similar to yours. Many times the behaviors (difficulty going to sleep, continual stalling, "needing" to go to the bathroom, etc) are symptoms of another issue. It could be something that has made him feel insecure and he needs additional reassurance at night...he may be experiencing separation anxiety...he may be testing the limits...or, it could be as simple as he is actually over-tired. Over-tired children and babies don't sleep well. In order to fight fatigue their bodies release adrenaline, which causes them to be more alert and awake...therefore, having a more difficult time falling asleep and staying asleep.
Without knowing your particular situation, it's difficult to know exactly what advice to give, however you can begin eliminating some of the possibilities. Purposefully spend more one-on-one time with him before going to bed to help ease his insecurities. Decide what your limits and boundaries are and then stick to them. Be consistent in how you deal with his wakings. Offer incentives and positive reinforcement...give him a reason to stay in bed. And, evaluate how much sleep he is getting. Every child requires a different amount, but often we under estimate how much sleep children need.
I hope this helps.
A. C.
www.babyyouconsulting.com