There are actually far more dangerous pathogens in the typical human mouth than there are in your anus/rectum. The mouth is an "entry point" into the body. The mouth is the favorite way of many bad germs to get into our body 24/7. Examples of how deadly mouth bacteria are can be found in the occasional case of fatal septicemia resulting from a mouth piercing that allowed "mouth bacteria" into the blood stream. Once there it went crazy and killed the person. The majority of people in the USA have oral herpes, not anal herpes. Those that have anal herpes got it from someones mouth. The Anus is an "exit point." It is literally the "opening to inside your body." That being the case, if it were loaded with dangerous germs, you'd be extremely sick if not close to death. The human body cannot survive long with a butt load of dangerous germs living in the anus or rectum. The Anus is part of the intestinal tract and in a generally healthy person is home to "good bacteria." They work with your body to keep you healthy, not make you sick. Licking the anus of a generally healthy individual without parasites or bacterial infection of the intestines nor viral is far less dangerous than kissing that person in terms of germ transfer. You are far more likely to get almost every venereal disease from kissing someone without even having sex than you are from licking their anus. The symptoms of many venereal diseases in the mouth are asymptomatic or almost so. At most they might cause a scratchy throat - but nothing that would stop someone from swapping saliva and spreading their case of oral VD, something which the NIH has recently become aware is actually a big factor in their ability to control the spread of syphilis - they assumed incorrectly it was almost always due to genital contact. An "unhealthy" anus on the other hand is NOT something most people would touch or even come near. Most people find other people's anal scent offensive, and that alone is enough reason to steer clear, even if it's harmless. Add on top of that odor the excessive flatulence and mucus discharges that would accompany an anal infection and you get something that would make most people pass out before they ever got close enough to contract anything. Ironically, if you are one of those people who has problems with his digestive system (outside of parasites) or after a round of harsh antibiotics have seriously upset your internals, licking a generally healthy person's anus could be a very good healthy smart thing to do, for it is the quickest way you can gain access to a butt load of "healthy, vigor-restoring good bacteria" in that person's body. Lick them and many will survive the passage through the stomach and make a new home for themselves in your intestines and immediately set to work repairing your intestinal problems by restoring the balance you need to have properly functioning, healthy digestive tract. HOWEVER, conceptually speaking licking someones anus is one of the most repulsive things many people can think of doing. So even if it is a great idea to easily solve many common intestinal ailments, it's extremely unlikely to catch on. Only when it comes to parasites is licking an anus "high risk" but fortunately in the western world parasite problems are often big news, because it's so rare. If one lives in a 3rd world country, because the parasite problems are so widespread, anus licking could be quite detrimental to your health.
