I'mCustomerand I would be glad to help with your question about Sassy. I'm so sorry about the loss of your friend: you are very kind to have adopted Sassy.
It's great that Sassy's recent blood work was normal. Do you know if a urinalysis was performed? That would be a great next step to rule-out a urinary tract infection as a cause of frequent urination. If her urinalysis is normal, then you may consider stress as you suggested as a potential cause before moving on to other diagnostics like imaging for bladder stones, etc.
The blood in her feces and frequent defecation are signs of colitis (inflammation of the large bowel. It is possible that stress and diet have played a role in the development of this problem. It could be seasonings on the meats you fed (best to cook non-seasoned chicken just for Sassy) but it might have been the dog foods you have been trying to get her to eat. If possible, I'd try to feed whatever she was used to eating before. Any sudden diet change has the potential to trigger intestinal upset.
Water loss in the stool due to colitis will increase water intake so keep that in mind as you observe Sassy drinking more right now. When blood is in the stool, I do recommend a visit to the vet for an exam, fecal test for parasites and often a course of Flagyl antibiotics to prevent secondary infection and reduce inflammation in the colon. It is best to nip this in the bud and hopefully avoid a more serious problem such as hemorrhagic gastroenteritis that can develop in some dogs that get colitis.
A bland diet (high fiber if possible) is helpful as are probiotics. Please note this probiotic is also used as a flavor enhancer for finicky dogs so hopefully Sassy would like it.
Fiber Supplement: 1 teaspoon canned pumpkin in food twice daily OR 1/4 teaspoon plain Metamucil in food twice daily
Diet: white chicken breast with no skin or fat and boiled white rice OR prescription dog food such as Hill's i/d low fat, Hill's w/d
I hope that the information I provided has been helpful. Please remember to select REPLY TO EXPERT if you have more questions or would like additional information. It is my goal to provide you with the most complete information possible prior to you leaving a feedback rating. If you received all the information you needed, then kindly submit a rating.