thanks for the advice ...you know I'm not 100% certain it's coming from her vagina. Something you said kind of made sense - the anal gland. When she has a poo she will often sit down really fast and do this kind of spinning thing while she sits. She doesn't scoot but definitely does squish her bum many times after she goes. I will be taking her to the vet though....when I think about this, it makes alot of sense. She's constantly sitting and kind of squirming. I have dewormed her too but I think the anal gland material may just be what is happening. Thanks.
Light brown could be either old blood or feces, or even anal gland material. Since your dog has been spayed, I think you need a vet to take a look at the problem. If you are certain this material is coming from the vagina, there are any number of things that could be happening including a vaginal infection or even a fistula that is allowing feces to drain through the vagina. There's no point in wondering and worrying - just go ahead and get a professional opinion now so the problem doesn't get worse and more expensive. :-)