Actually, what the OP is describing would fall under Section 504. I would recommend that the OP take a peek at
Protecting Students With Disabilities for more information.
Here is a snippet:
The Section 504 regulations require a school district to provide a "free appropriate public education" (FAPE) to each qualified student with a disability who is in the school district's jurisdiction, regardless of the nature or severity of the disability. Under Section 504, FAPE consists of the provision of regular or special education and related aids and services designed to meet the student's individual educational needs as adequately as the needs of nondisabled students are met.
(emphasis added)
The hurdle that the OP will have to overcome is the unwillingness of the doctors to actually
diagnose the child. OP should request that the district evaluate the child for special education services.
That's begging the question. Your source states:
"To be protected under Section 504, a student must be determined to: (1) have a physical or mental impairment that substantially limits one or more major life activities; or (2) have a record of such an impairment; or (3) be regarded as having such an impairment. Section 504 requires that school districts provide a free appropriate public education (FAPE) to qualified students in their jurisdictions who have a physical or mental impairment that substantially limits one or more major life activities."
I don't see any evidence at all that the child meets ANY of those requirements. In fact, the doctor has certified that the child is able to go to school, so the child does NOT meet the requirements.
I really object to the use of money that should be used on educating the children who can actually be bothered to go to school to provide special care for a kid who simply doesn't want to go - at least as far as any evidence is concerned.
Give me a break - fatigued? Try getting my daughter up in the morning. ALL kids are tired when they wake up if they don't want to go to school. General anxiety disorder? Translated, that's "there's nothing wrong with the kid but Mom is driving us crazy asking for a diagnosis".
Legally, the kid needs to be in school unless a doctor says otherwise. The doctors who have examined the child say the child can be in school. The kid needs to be in school - even if he's a little fatigued. Stop covering up for his malingering. OR, see a specialist to see if there's something really wrong. But you can't simply continue to say "he's too tired to go to school even though the doctor says he can go".