Why it is done this way
Ordinary medicine, with more time and a wider panel
Nothing here is exotic. It is standard laboratory medicine, ordered properly and read against you rather than against a population.
A fifteen-minute appointment and a screening panel is a reasonable system for acute illness. It is a poor system for someone who has felt wrong for two years.
The difference is not a secret protocol. It is a long first visit, a panel three times the usual size, and someone sitting down to explain what came back.