Under the general category of
analingus, butt sucking involves a vigorous suction motion to be done by the mouth on the anus, rather than mere licking. In fact, the use of the tongue in the case of butt sucking is optional. If there are turds in said anus, butt sucking may lead to something under the header of
scat. The resulting stimulation is different than mere licking, and has been purported to resemble the feeling of involuntary dumping. See:
incontinence.
