Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
Since your girl has multiple medical issues, this is most likely due to a mild digestive disturbance. the mucous forms due to being in the colon too long and this is because it is painful for her to have a bowel movement. The best thing to try is the following:
Fast your girl for 12-24 hrs to allow the digestive tract to calm down and heal.
Give your girl Pepcid AC or Famotidine at 0.5 mg per pound every 8 hrs. That can be purchased over the counter at the pharmacy.
Give only small amounts of water during the fast or ice cubes
After the fast, feed rice and boiled chicken (2/1)
If this helps, then wean her back to the foods that she will eat...if not, have your vet examine her...there may be a form of Inflammatory Bowel Disease taht would require other medications.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, XXXXX XXXXX