Here is how to do it if (like here where I am) the popo requires YELLOW pee that is BODY TEMP and THEY VIEW THE STREAM EXITING YOUR PENIS:
Get a vitamin B tab, put it in water (about a large drinking-glass worth) of your choice (tap, distilled, whatever as long as it's clean) in a bowl. Let it sit while slowly stirring until it reaches the color yellow that makes you happy, remove remainder. Now warm the H2O in a mic, take a thermometer and check it until it's around 95-100 degrees. Get yourself either an infant ear syringe (douche) or just a reg one that is rather large (remove/discard needle, unless you're into pain). Now (and I realize this might not be the phashizzle for everybody, but hey, if you MUST pass...) take a real good pee (BTW-I forgot to say NOT to drink allot-you want THIS shit to be in your bladder and NOT your own urine) and then get some of the water into the syringe or douche. Sit on the toilet to catch any overspray/drops. Insert your choice of implement into the opening of your schwanz. Try to relax your peehole sphincter a little while holding everything in place and push. It might take 3-4 times but you WILL fill your bladder. Now, assuming you've done this immediately prior to showing up and have not drank anything in the preceding 12 hours-THEN YOU WILL PASS GUARANTEED! It is the right color (they don't even suspect), the right temp. and it comes out straight from the end of your meat enema.
ENJOY!