What do you think of my cat's health problem?

Last January I took my 16 year old female cat (Sheba) to the veterinarian because I saw small amounts of blood in her stool (also large amounts of hair). She was also vomiting a lot, losing weight and hiding in the closet.The vet examined Sheba (and 2 of her stool specimens) and said that she likely has a large hair and or a food allergy (no ova or parasites were seen in her stool specimens). He prescribed “Vetasyl” (high fiber daily supplement).

Sheba seemed to improve over the next 3 months as I saw less blood in her stool, less vomiting and less hiding behavior. Suddenly a week ago Sheba occasionally didn’t use her cat box (I maintain it very well) and deposited large amounts of gross blood on the floor next to her cat box.

I took Sheba back (on 5–26-16) and showed him the blood pictures. The vet examined her again and said that she is ok and prescribed a probiotic (“Pro Plan FortiFlora”). I was told to also closely monitor Sheba’s weight (She’s down to 8.5 lbs, down from 13 pounds a year ago). The vet told me to call him next week to let him know how Sheba is doing. If Sheba does not improve then the vet wants to tale blood specimens.

I suspect that there is something more serious going on in Sheba’s colon than just a hairball or food allergy. Perhaps cancer.

What do you think?

Has your cat had symptoms like Sheba’s?

Thank you for your time.