A woman visits her gynecologist, complaining of vaginal discharge, irritation, and pain during intercourse. Upon examination, her doctor observes a yellowish-green color to the discharge and a foul-smelling odor (but not "fishy" smelling.) What disease does the woman most likely have?

The woman most likely has trichomoniasis.

Explanation:

Trichomoniasis can be described as a common type of sexually transmitted disease which is caused by a protozoan parasite Trichomonas vaginalis.

The symptoms of trichomoniasis include

1) Itching, burning, redness or soreness of the genitals

2) Discomfort at the time of urination

3) A change in their vaginal discharge (i. e., thin discharge or increased volume) that can be clear, white, yellowish, or greenish with an unusual fishy smell.