Here is a list of what many doctors refer to as Lavender diseases. They occur with extraordinary frequency among male homosexuals who engage in anal intercourse.
Anal Cancer
Chlamydia trachomatis
Cryptosporidium
Giardia lamblia
Herpes simplex virus
Human immunodeficiency virus
Human papilloma virus
Isospora belli
Microsporidia
Gonorrhea
Viral hepatitis types B & C
Syphilis
Not listed:
It can REALLY hurt someone's butt.