Boils on the buttocks result from staphylococcal bacteria, according to WebMD. The bacteria enter the body when the skin sustains a cut. They can also penetrate through the skin by moving downward along the hair follicle.
Conditions that may expose the skin to boil infection include diabetes, malnutrition, poor hygiene, skin irritating chemicals and immune system disorders, notes WebMD. Aside from the buttocks, boils can also attack the face, shoulders, armpits and eyes.
To prevent the spread of boils, individuals should properly wash bedding, clothes and towels that an infected person has used, advises WebMD. Practicing proper hygiene and maintaining good health also help prevent boils.