Think hospitals are no fun? Step inside Sacred Heart, where the interns are insecure, sarcastic pups; the doctors’ favorite stress-relieving technique is insulting them in the most creative and verbose ways imaginable; and the janitor is deliciously Machiavellian. Season two of “Scrubs” is out on DVD, close on the heels of the first, and this lightning-fast, offbeat comedy doesn’t even have time to flirt with a sophomore slump. As the frazzled interns enter their second year, Elliot (Sarah Chalke) is mocked for dating a “murse” (male nurse), while J.D. (Zach Braff) is, as always, being called “Suzie,” “Martha” or any other girl’s name by Dr. Cox (John McGinley) while trying to avoid his mop-wielding arch-nemesis in the halls. Just imagine Sacred Heart as high school, then take a scalpel to it. More bizarre characters, more razor-sharp dialogue and more perfect comebacks than any other comedy on television — prepare to find more of the same all around, but no need to change prescriptions in this show’s case.