What can cause yellow vaginal discharge with a fishy odor?

Bacterial vaginosis. A fishy odor is most commonly caused by overgrowth of certain bacteria in the vagina. There are several possible causes and while it is not necessarily a sexually transmitted infection it could be. A diagnosis should be obtained by pelvic examination. There are characteristic findings on microscopic evaluation of the discharge. See your doctor for further evaluation.
BV. Sometimes disturbances to the natural bacteria in your vagina (douching, irregular bleeding, unprotected sex, etc) can allow abnl bacteria like Gardnerella to overgrow and cause a fishy odor. It's not sexually transmitted, but can be treated w/ Metronidazole (Flagyl)/Clindamycin/Boric Acid. See your GYN for a prescription and be examined for other potential causes. Nothing urgent/dangerous though.

Related Questions

Yellow clumpy vaginal discharge sometimes clear, no odor, no itch, negative for c&s test, wet mount and pap test. What else can cause yellow discharge?

Treat for best guess. Diagnosis of vaginal discharge can be difficult. Yellow color suggests infection. Depending on exact tests done, some infections can be missed, e.g. gonorrhea, chlamydia, trichomonas. Talk to your doctor about being retested. If available, include the new DNA test for trich, much more accurate than wet mount. It may be necessary to treat for the best guess, without proof of diagnosis. Good luck!
Probably normal. What you describe is classic for a yeast infection, but that almost always causes major itching! Bacterial vaginosis discharge is typically grayish, cloudy & fishy smelling. Trichomoniasis is heavy, yellow/green, with odor. Gonorrhea or chlamydia is thick, yellowish/greenish, with discomfort. Yours is likely normal-the result of fluid produced by glands lining the vagina and cervix. OK to observe.

What are the main causes for yellow vaginal discharge if not sexually active, no burning/itching/pain/Odor? Is it normal?

Needs testing. Vaginal discharge requires an examination to determine the cause and treatment. Bacterial vaginosis is the most common cause and often has a vaginal odor. Vaginal itching can be a sign of a yeast infection. Vaginal discharge can occur in women who are not sexually active.

My vaginal discharge is yellow. There is no itching or smell. What can cause this?

Could be normal. If there is no itching or odor, the discharge may be normal. If you have had any new unprotected sex partners or if your partner has had another partner, it could be a sign of other infection such as gonorrhea or chlamydia.