She probably does need to see the vet if she has been having loose stools long enough to lead to anal gland problems. Diarrhea can be caused by a large number of things including an unusual treat, irritable bowel syndrome, disease, bacteria or protozoan infection. If your dog is eating and drinking normally, Kaopectate at 1 teaspoon per 5 pound every 2 - 6 hours or Immodium at 1 mg per 15 pounds one or two times a day can be given for diarrhea. Canned pumpkin (not pie filling) will also absorb excess fluid in the bowel with just a spoonful added to the dog's food. Some experts will recommend a bland diet for a few days of boiled chicken and rice. If the diarrhea continues, have your dog tested for parasites such as worms or a protozoan infection such as coccidia or giardia. Here are sites on worms, coccidia and giardia, which you may find informative.
If your dog is dragging their behind on the ground or carpet and their anus area has a bad odor and swollen, it can be symptoms of an anal gland problem. You will want to check to see if your dog's anus is swollen. This may cause a dog to continue to lick the area.
The anal glands are 2 sacs on either side of the anus at about the 4' o'clock and 8 o'clock positions. If your dog is continually licking their anus and dragging it, it could also indicate that they are full. This problem can usually be resolved by emptying out the glands. To empty them or express them, you will want to cover the area with a tissue and press your finger on the dog's anal glands with an upward motion. A foul smelling liquid should come out. If nothing comes out and your dog appears to be in pain, you should take him to the Vet. Your vet or groomer can do this easily, as he is experienced at it.
Excellent site on anal glands
If no lump in area It could also be tapeworm infestation. Tapeworms release segments that exit the anus and spread tapeworm eggs into the environment. They can cause severe itching in some dogs. They can usually be seen in the stool and are small about 1/2 inch moving things. If the stool has dried, they look like rice in the stool or stuck in the hair around the anus. Drontal plus is also a prescription product and is used for the treatment of Tapeworms, though dewormers with praziquantel work well against tapeworms.
Frequent urination usually goes along with increased thirst. We see this when a female is in heat, but we also see it when they have uterine infection or urinary tract infections as well. This site discusses UTI's and various medications used for treatments.
I'd skip the groomer and take her to the vet so she can be tested for a uti and for parasites. While you are there, you can have her anal glands expressed. Ask your vet to show you how to do this so in the future, you can keep them done.
Hope this helps.