Feces, while not generally classed as a body fluid, are often treated similarly to body fluids, and are sometimes fluid or semi-fluid in nature.
Internal body fluids, which are not usually leaked or excreted to the outside world, include:
Bodily fluids are regarded with varying levels of disgust among world cultures, including the Abrahamic faiths (Christianity, Islam, Judaism) and Hinduism. In Hinduism substances that have left the body are considered unclean, although there are some sects which smear cremated body ash on their foreheads as symbolic gestures.
Feces and urine have been used by religions on every continent for atonement, rites of passage, and funerary rites.
One interesting example is the alleged consumption of some ancient sects of the urine of people intoxicated with hallucinogenic mushrooms or creepers, as the urine contained high concentrations of the drug and could be "re-used."
Attitudes concerning bodily fluids aside, there is a long human history of their use in religion, medicine, art, sex, and folklore. Some believe that the tradition of shaking hands with the right hand stems from using the left hand to clean up after defecation, as a result, shaking hands with the left hand is considered insulting in many cultures.
A relatively new trend in contemporary art is to use body fluids in art, though there have been rarer uses of blood (and perhaps feces) for quite some time, and Marcel Duchamp used semen decades ago. Examples include:
Safer sex practices try to avoid exchanges of body fluids.