Sexual fetishism or erotic fetishism is a sexual fixation on a nonliving object or nongenital body part. The object of interest is called the fetish; the person who has "a fetish" for that object is a fetishist. A sexual fetish may be regarded as a non-pathological aid to sexual excitement, or as a mental disorder if it causes significant psychosocial distress for the person or has detrimental effects on important areas of their life. Sexual arousal from a particular body part can be further classified as partialism.

While medical definitions restrict the term "sexual fetishism" to objects or body parts, "fetish" can also refer to sexual interest in specific activities in common discourse.

In a review of 48 cases of clinical fetishism, fetishes included clothing (58.3%), rubber and rubber items (22.9%), footwear (14.6%), body parts (14.6%), leather (10.4%), and soft materials or fabrics (6.3%). A 2007 study counted members of Internet discussion groups with the word "fetish" in their name. Of the groups about body parts or features, 47% belonged to groups about feet (foot fetishism), 9% about body fluids, 9% about body size, 7% about hair (hair fetish), and 5% about muscles (muscle worship). Less popular groups focused on navels (navel fetishism), legs, body hair, mouth, and nails, among other things. Of the groups about clothing, 33% belonged to groups about clothes worn on the legs or buttocks (such as stockings or skirts), 32% about footwear (shoe fetishism), 12% about underwear (underwear fetishism), and 9% about whole-body wear such as jackets. Less popular object groups focused on headwear, stethoscopes, wristwear, and diapers (diaper fetishism).

Paraphilia (previously known as sexual perversion and sexual deviation) is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. Such attraction may be labeled sexual fetishism. No consensus has been found for any precise border between unusual sexual interests and paraphilic ones. There is debate over which, if any, of the paraphilias should be listed in diagnostic manuals, such as the "Diagnostic and Statistical Manual of Mental Disorders" (DSM) or the International Classification of Diseases (ICD).

The number and taxonomy of paraphilia is under debate; one source lists as many as 549 types of paraphilia. The DSM-5 has specific listings for eight paraphilic disorders. Several sub-classifications of the paraphilias have been proposed, and some argue that a fully dimensional, spectrum or complaint-oriented approach would better reflect the evidence.

Coprophilia (from Greek "κόπρος, kópros—excrement" and "φιλία, philía—liking, fondness"), also called scatophilia or scat (Greek: "σκατά, skatá-feces"), is the paraphilia involving sexual arousal and pleasure from feces. In the "Diagnostic and Statistical Manual of Mental Disorders" (DSM), published by the American Psychiatric Association, it is classified under 302.89 – Paraphilia NOS (Not Otherwise Specified) and has no diagnostic criteria other than a general statement about paraphilias that says "the diagnosis is made if the behavior, sexual urges, or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning". Furthermore, the DSM-IV-TR notes, "Fantasies, behaviors, or objects are paraphilic only when they lead to clinically significant distress or impairment (e.g. are obligatory, result in sexual dysfunction, require participation of nonconsenting individuals, lead to legal complications, interfere with social relationships)".

Although there may be no connection between coprophilia and sadomasochism (SM), the limited data on the former comes from studies of the latter. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. In a separate article analyzing 12 men who engaged in bestiality, an additional analysis of an 11-man subgroup revealed that 6 had engaged in coprophilic behavior, compared with only 1 in the matched control group consisting of 12 SM-oriented males who did not engage in bestiality.

Salirophilia is a sexual fetish or paraphilia that involves deriving erotic pleasure from soiling or disheveling the object of one's desire, usually an attractive person. It may involve tearing or damaging their clothing, covering them in mud or filth, or messing their hair or makeup. The fetish does not involve harming or injuring the subject, only their appearance.

It is related to wet and messy fetishism, bukkake, omorashi, mysophilia, urolagnia and coprophilia, but extends to other areas such as forcing the partner to wear torn or poorly fitting clothing and other actions which would render them normally unattractive.

The fetish sometimes manifests itself in the defacing of statues or pictures of attractive people, especially celebrities or fictional characters. It is common to refer to the practice involving ejaculating on a photo as "facepainting". The fetishist finds this sexually exciting, rather than mere vandalism. They sometimes form collections of defaced art for future enjoyment. A video of the fetishist ejaculating on a picture of someone or a photo depicting the result is known colloquially as a "tribute".

The term comes from the French for soiling, "salir". In cases where the fetish is obsessive it is called saliromania. It is frequently confused with salophilia, an attraction to salt or salty things (especially body sweat) that derives from the Latin for salt, "sal".

Many terms have been used to describe atypical sexual interests, and there remains debate regarding technical accuracy and perceptions of stigma. Sexologist John Money popularized the term "paraphilia" as a non-pejorative designation for unusual sexual interests. Money described paraphilia as "a sexuoerotic embellishment of, or alternative to the official, ideological norm." Psychiatrist Glen Gabbard writes that despite efforts by Stekel and Money, "the term "paraphilia" remains pejorative in most circumstances."

Coinage of the term "paraphilia" ("paraphilie") has been credited to Friedrich Salomon Krauss in 1903, and it entered the English language in 1913, in reference to Krauss by urologist William J. Robinson. It was used with some regularity by Wilhelm Stekel in the 1920s. The term comes from the Greek παρά ("para") "beside" and φιλία ("-philia") "friendship, love".

In the late 19th century, psychologists and psychiatrists started to categorize various paraphilias as they wanted a more descriptive system than the legal and religious constructs of sodomy and perversion. Before the introduction of the term "paraphilia" in the DSM-III (1980), the term "sexual deviation" was used to refer to paraphilias in the first two editions of the manual. In 1981, an article published in "American Journal of Psychiatry" described paraphilia as "recurrent, intense sexually arousing fantasies, sexual urges, or behaviors generally involving:

- Non-human objects

- The suffering or humiliation of oneself or one's partner

- Children

- Non-consenting persons

Mysophilia relates to soiled or dirty material or people. Mysophiliacs may find dirt, soiled underwear, feces, or vomit to be sexually arousing.

It is possible for people with mysophilia to be aroused by unclean locales, such as an alleyway, or a dirty room/bathroom; wearing the same clothing for many days at a time; or not bathing, from mere days to several weeks.

The Cleveland steamer is a colloquial term for a form of coprophilia, where someone defecates on their partner's chest.

The term received news attention through its use in a U.S. Congress staff hoax email and being addressed by the United States Federal Communications Commission.

Wet and messy fetish (WAM), also known as sploshing, is a form of sexual fetishism whereby a person becomes aroused when copious amounts of a substance are applied to the naked skin, face, or to clothing. Several websites are dedicated to WAM.

Many people with WAM fetishes are drawn to the tactile sensations of wet or messy substances against their skin. Other individuals simply prefer the visual appeal of others getting wet or messy with products that have different textures, consistencies and colours. A subject will often be pelted with cream pies (sometimes using shaving foam rather than real cream pie filling), have slime dumped on them, or sit on cakes. Another common theme is the pouring of substances inside clothing while it is being worn; clothing chosen for this can vary from swimsuits or underwear to full outfits. Normal street clothes, either casual or office wear, are commonly featured in WAM productions, but many other types of outfits, from wedding attire to industrial overalls or more specialist fetishwear such as PVC, latex, or leather items may be used. White items are particularly popular with some fans of this fetish.

Messy substances most commonly focused on by WAM participants include whipped cream, raw eggs, milk, lotion (see lotion play), paint, oil, mud, pudding, chocolate sauce, fruit juice, beer, shaving foam, custard, baked beans, treacle, ketchup, ice cream, peanut butter, slime, and cake batter, among others.

A fetish for bodily fluids such as feces, urine, vomit, semen, and female ejaculate is not considered part of WAM. The former three are typically considered coprophilia, urophilia, and emetophilia; urophilia is somewhat commonly found in mainstream pornography. The latter two are also somewhat mainstream.

WAM fetish videos (made by both fans and commercial producers) may include nudity and sexual acts, while others may only feature fully clothed participants. Videos can be seen frequently public video hosting sites like YouTube. Some of these videos are flagged but most of them remain available despite the sexual undertones, mainly because a large majority of wet and messy videos posted publicly do not include nudity and are therefore considered suitable for all audiences to view. Indeed, not only is much WAM video content indistinguishable in any easily defined sense from the kind of slapstick featured in mainstream entertainment, but scenes of slimings or pieings from the mainstream media are often compiled and marketed by producers towards a WAM fetishist target audience.

There is some crossover between the wet and messy fetish and clothing destruction fetishes. Some WAM productions will see models start out fully dressed, usually in quite smart outfits such as formal dresses or suits; they will then be covered in messy substances, after which their messy clothes are cut up, typically with scissors, leaving them naked or nearly so.

WAM is sometimes also combined with bondage, where a subject is first restrained or chained up and then hosed down or messed up. Wet and Messy fetishism lends itself well to domination/submission role-playing.

"Cake Sitting" (the act of deliberately sitting on a large cake or gateaux, either clothed or nude) is often considered a sub-fetish in its own right, but may be linked to the Crush fetish. While participants who sit on cakes for pleasure will do so for the tactile sensory experience, or as part of submissive role-playing, those who enjoy watching the act will often focus specifically on the crushing of the dessert as a visual stimulus for a sexual reaction.

Coprophobia is fear of or aversion to feces or defecation

Unlike coprophilia or coprophagy, coprophobia appears to be unknown in the animal world, with the exception of humans. In fact, the attitude to feces and defecation has become a cultural taboo.

The fecal–oral route (or oral–fecal route or orofecal route) describes a particular route of transmission of a disease. Pathogens in fecal particles pass from one person to the mouth of another person. Main causes of fecal–oral disease transmission include lack of adequate sanitation (leading to open defecation), and poor hygiene practices. If soil or water bodies are polluted with fecal material, humans can be infected with water-borne diseases or soil-transmitted diseases.

Fecal contamination of food is another form of fecal-oral transmission. Washing hands properly after changing a baby’s diaper or going to the bathroom can prevent diseases from spreading.

The common fecal-oral routes are fingers, flies, fields, fluids, food. Diseases caused by fecal-oral transmission include diarrhea, typhoid, cholera, polio and hepatitis.

The list below shows the main diseases that can be passed via the fecal–oral route. They are grouped by the type of pathogen involved in disease transmission.