Affordable food for sensitive cat

My 1 year and 4 month old Molly, keeps getting loose stools, so I think feeding food for a sensitive belly might help?
Can anyone advise which is the best?
The last few days there has been a trace of blood on the top of her poo. We asked the vet what could it be when she went for her vaccinations on Friday, and the vet said as long as it's only on top and doesn't go on too long it probably means she's passed a large movement and damaged her colon, which should pass. That doesn't stop me worrying though!

Okay, first off, what food is she eating now? That really makes a difference. What brand? Wet, dry or raw?

If she is not on raw, that would probably be the best diet for a sensitive stomach but I totally understand that it is not for everyone. If you can't go with that, a grain-free canned food like Wellness grain-free, Weruva or Nature's Variety may help. Unfortunately, these foods are expensive, but if you are looking for something a little lower in price then you could go with Authority. If your cat is on dry food, the reason for her upset stomach could be the dry food.

Hi, she is on a supermarket food, felix, she has half a pouch of wet food twice a day, and they have as many biscuits (whiskas) as they like as they are left out all day for them. So, wet and dry food.,she has some access to outside as well, and she hunts.

You might try what is called a "quiet diet" for a while...it worked for our Dolly who had trouble tolerating anything! dry, wet, grain, no grain, nothing seemed to work until we tried this:

approx. 1/2 boiled chicken, no bones

approx. 1/2 canned cat food

add table spoon cooked rice

add generous table spoon of pumpkin

some chicken broth to wet

grind the whole thing into a paste and feed ...store in ****.when not used ...should keep for 5-6 days...your cat will let you know when the "fresh" taste is going

If it is going to work you should notice a difference in 1-2 days

You may have to keep your cat on this for several months, trying the old routine every so often to see if they can tolerate it

Good luck...I know what you are going through