A vaginal treatment composition that rapidly forms a gel when placed into contact with monovalent or polyvalent cations, such as sodium (Na+) and calcium (Ca2+) cations naturally found in vaginal mucosa, is provided. The gel may form in less than about 1 hour, in some embodiments less than about 1 minute, and in some embodiments, less than about 30 seconds. Among other things, such rapid gelation reduces the likelihood of leakage during use. In addition, because the gel may form intravaginally, it is more likely to retain its structure and shape over an extended period of time. In this manner, the gel may provide the prolonged release of a therapeutic agent that inhibits and/or treats vaginal infection. For instance, the gel may remain within the vagina for about 2 to about 48 hours to provide the desired effect.