No Child Left Behind' requires states and school districts to ensure that all students are learning and are reaching their highest potential. Special education students should not be left out of these accountability mechanisms.
If a child is still wetting the bed when he's 8, it's usually simply because he sleeps very soundly.
If the child is older, have them strip and change the sheets in the middle of the night. Not as a punitive measure, but to become more aware.