When disabled veterans have their yearly lab tests done (blood&urine) for diabetes does the VA...
A. Check to see if you have your prescribed meds in your system?
B. Check for illegal drugs in your system?
I don't know that vets have yearly tests for diabetes. You may be referencing routine lab work (blood tests and urinalysis) during physicals that may note high blood sugars as well as high cholesterol and many other abnormalities.
You may at that time be checked for illegal drugs. That is almost accidental because sometimes VA does check you for legal drugs. Here is how it works...
If you have a condition that causes chronic pain, you may be on long term therapy with oral narcotic medications. In both the civilian world as well as the veterans world, most treating caregivers today require that you will sign a "pain contract". That agreement tells your doctor that you will only take the narcotic strictly as prescribed and that you won't share it with anyone else. It will also say that you agree to take a drug test to see if there is a therapeutic level of the drug in your system. These tests may be random or scheduled.
There has been an infrequent problem that patients will use their narcotics to turn a profit...they may sell the pills to others. If you are tested for your particular drug and you do not have any of it in your system, you'll have some explaining to do. For example, if your prescription says you are to take 3 pills each day for your pain and you have none of the medicine in your blood or urine, that would indicate that you haven't taken the medicine for days and that you probably don't need it.
When you are tested, the most frequent test is by urinalysis. Each test kit has a cost associated with it. There are different types of test kits that detect different types of drugs. The lower cost testing supplies usually test for 4 drugs at the same time. Other kits will test for 6 or 8 or more. As you would guess, the more drugs detected, the higher the cost of the kit.
Much of the testing in both civilian and VA and military settings is done with a standardized 4 drug detection kit. The test of your urine would show the presence of narcotics (Vicodin, Oxycontin, morphine, etc.). marijuana, cocaine (or crack) and amphetamines. In some tests benzodiazepines (Valium and similar) may be detected.
Therefore, if you are tested to ensure that you are taking your prescribed medication and you have been smoking marijuana, you'll likely get a call from your doctor.
VA has recently issued a policy about the use of marijuana by patients. State laws regarding medicinal marijuana are changing across America but federal laws aren't. VA is a federal institution and must walk a fine line between condemning the use of marijuana or endorsing it.
The policy is here www1.va.gov/vhapublication/ViewPublication.asp?pub_ID=2276
What they did in the policy statement was to leave it up the the individual treating doctor as to how to handle such a thing. VA will not allow doctors to prescribe medicinal marijuana but your doctor can pretty much ignore your use of it if he or she doesn't see a problem.
If your doctor believes that you have a conflict with the use of prescribed medications and smoking marijuana, you may be instructed that you must make a choice of marijuana or prescribed medications. That is strictly a therapeutic decision by the provider and little appeal is available should it happen to you.
Beyond all that, to my knowledge veterans are not routinely tested for illegal drugs. The expense alone would be huge and in a more or less routine circumstance, testing of all patients at a given facility may show that hundreds or even thousands were using marijuana. The question of "What then?" arises. Once VA identified all these veterans what should they do?
There are instances where mental health patients who are taking psychotropic drugs will be tested to ensure that they are not taking illegal drugs. That's a very serious situation as the mental health patient can negatively affect the treatment plan by mixing their prescribed medicines with recreational drugs. Patients who are candidates for organ transplants may also be counseled (and tested) about using recreational drugs because of the amount of anti-rejection medicines they are likely to be required to take.