What are the causes for Bartholin's Cyst?

A Bartholin's cyst develops when the duct exiting the Bartholin's gland becomes blocked. The fluid produced by the gland then accumulates, causing the gland to swell and form a cyst. An abscess occurs when a cyst becomes infected. Bartholin's abscesses can be caused by any of a number of bacteria. These include bacterial organisms that cause sexually transmitted diseases such as chlamydia and gonorrhea as well as bacteria normally found in the intestinal tract, such as Escherichia coli. It is common for these abscesses to involve more than one type of organism.

Source: http://www.emedicinehealth.com