Many men have sexual fetishes, whether mild or strong, that they find more interesting rather than just vaginal intercourse. Often, a fetish can be experienced during an extended foreplay that eventually leads to "natural intercourse". All you need is a willing partner that has a similar interest or one that at least will go along with your fetish, as long as it ends up in a more conventional fashion. Mild fetishes, such as interests in body parts are quite common, however the scat fetish may prove to be more of a challenge in finding an active partner. Also, don't count out "natural intercourse", once you are aroused, until you try it with the right partner.
It appears that you need to approach a sex consultant to find the cause and remedy to solve your disorder.
There are probably people who like every kind of fetish in the world. If it bothers you that you have the fetishes, you could talk to a therapist, but if you decide to go ahead with a life that features fetish sex instead of standard intercourse, that it possible also, I assume. It just might cut down your overall number of potential sexual partners.