A remedial simply means they need more information about something on your exam.
No waivers are needed for a "remedial" - only for disqualifications.
It could be a simple administrative paperwork matter, it could be a request for some past medical records, or it could be an additional medical test to clarify, confirm, or exclude a condition that may disqualify you.
Follow the instructions carefully and promptly on the letter you will receive. It will tell you exactly what they want/need to complete your medical status report.