The solution for the constipation is more "P" fruits and more fiber. He could also be lacking in magnesium which is found in green veggies. Also, water is helpful in keeping things running through the digestive system. Try to stay away from the breads and "white" foods. The bedwetting at this stage is odd. It usually starts earlier in childhood and then fades out as they get older. What does your doctor say about it. Could it be that he's sleeping deeper since he's getting older and nearing puberty? Maybe he needs to stop drinking fluids several hours before bedtime and make sure he goes to the bathroom before bed. He may need to see a urologist incase he has issues in that area. Don't overreact about it. Just keep him clean and dry as much as possible.
Good luck.