A group or individual major medical accident and health insurance policy or managed care plan amended, delivered, issued, or renewed after the effective date of this amendatory Act of the 95th General Assembly must provide coverage and reimbursement for amino acid-based elemental formulas, regardless of delivery method, for the diagnosis and treatment of (i) eosinophilic disorders and (ii) short bowel syndrome when the prescribing physician has issued a written order stating that the amino acid-based elemental formula is medically necessary.