Friend, when we see vomiting of undigested food it is called "regurgitation" as the food has not been digested. Possible causes could be esophagus disorders (megaesophagus, strictures, parasites), gastritis, tumors or even part of a systemic disease. So, treatment will be dependent on exact underlying cause.
At this stage, I would highly recommend you consider having her checked by your family veterinarian for xrays and blood work as initial screening test to determine the exact underlying cause. You see, pale gums is not a good finding this could be a sign of: Anemia, poor circulation, blood shifting to other organs, etc. I would try to get her in to see family vet as soon as possible for the above testing. If cost is a concern look into your local ASPCA or Shelter where they often offer veterinary services at a lower cost. In the meantime, this is what you can do:
1- Do not give things like Pepto Bismol or imodium. Start her on Pepcid AC (famotidine) 10mg 1/2 tablet every 12 hours for the next 2-3 days. You can buy Pepcid AC over the counter in any pharmacy.
2- No food or water for 3-4 hours. Need to give her gastrointestinal tract time to rest.
3- After 3-4 hours offer a small amount of water. Wait half hour, if no vomiting, offer small amount of rice (50%) and boiled boneless chicken or ground beef (50%) 4-6 times a day.
Note: Raise her eating and drinking bowl on to a small stool to force her to raise her head when she eats or drinks.
4- Follow up with your family veterinarian for a hands on examination, xrays and blood work as initial screening test.
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