Various excitation bacterial (Shigella, Campylobacter, or Salmonella), viral (hepatitis A, B and C viruses), and parasitic (Giardia sp or amoebae) -Be transmitted through sexual practices, particularly those in which participates a fecal-oral contamination can be. In order of decreasing risk these practices Oral-rectal anal genital Oral-genital genital genital intercourse are Although some of the bacterial and parasitic pathogens mentioned above can cause proctitis, they usually cause infections in the upper intestinal tract; Symptoms include diarrhea, fever, flatulence, nausea and abdominal pain. Multiple infections are common, especially in people who have many sexual partners and perform sexual practices where there is direct or indirect oral-rectal contact. Most of these pathogens can cause infections with no symptoms; asymptomatic infection is the rule with Entamoeba dispar (formerly Entamoeba histolytica), which often occurs in homosexual men. For the diagnosis and treatment of these infections s. elsewhere in the MSD Manual.