really the only thing necessary and recommended for someone in this age group in the absence of any symptoms is weight/height (to calculate BMI) and blood pressure. the national cholesterol education program recommends checking lipids starting at age 20, but the US Preventive Services Task Force, the agency that sort of sets the 'bare minimum' and evaluates the evidence for and against preventive services does not recommend lipid screening for males younger than 35. most insurance companies base their screening guidelines (if they even have any) on the USPSTF.
that being said, every professional society and specialty organization will have their own slant on things and doctors usually do their own thing anyway since most of us aren't driven by evidence. there's a lot of unnecessary physical exam going on in the US and it does not prevent disease.
one practical matter to be aware of is to find out if your health insurance covers preventive services. the majority of hmos and health insurers (including medicare) do not cover many preventive services, or if they do, it's by way of setting some 'standard of care'. so if you go for a 'physical' (whatever that is) you could potentially get stuck with a fairly large bill, especially if your doc goes fishing where they didn't need to. in case you are using school health insurance, you need to know if it's a preventive plan (which is usually pretty expensive, hence many schools don't offer this) or an accident plan (which only covers sick visits).
and 24 yo don't need rectals unless they are MSM.
