I took her to the vet week before last because she wasn't feeling well. The vet put her on metronidazole for diarehea and upset stomach. She said not to worry. I was feeding her rice and boiled hamburger, then slowly started her back on her dog food. Now she is just as she was before. I also switched dog food since the food I was giving her before she stopped eating.

If she was OK with the rice and boiled hamburger, go back to that until you can talk to your vet or one of the expert answers:)

I'm sorry she's not feeling well.:(

Her anal glands might be full after having diarrhea. The stool is typically firm enough to drain them during a bowel movement, but when loose they can get quite full and cause some discomfort.

I agree with teachnk, sounds like it could be anal glands.
Every time a dog goes to the toilet, if their stools are firm enough, a little bit of the fluid in the anal glands gets pushed out as well. If the stools are soft, then there is nothing pushing against the glands, and nothing coming out, leading to excess fluid and often infection.

Your vet will be able to empty them for you, you can do it yourself, but I warn you... it is messy, and there will most likely be vomit... coming from you.

Had to spread the rep Shaz, but... LOL LOL that is so true.

I am assuming she has been treated for worms? If that's all clear, my money is on the anal glands as well.