What will help?

[bleepingbleepybleep]

I've got an old, Jack Russel mix male, about 16 years old.

He's never had problems with food, has always eaten what he's given.

Few weeks ago, he needed some painkillers due to a sore leg(prescribed by a vet) he was supposed to be on then for a week, but I stopped after 3 days due to making him have diarrhea and since then, his diarrhoea hasn't stopped.

I called the vet who suggested chicken and rice, which I've tried, but it hasn't made any improvements

Any suggestions without going to the vet who will charge a fortune

No, you need to go to the vet. What pain killers did they give him and did he have any blood tests? NSAIDS can affect the kidneys, particularly in older dogs, which can give them a bad tummy.

Go back to the vet; mine would probably take bloods and urine sample at this point given the painkillers.

If bloods are clear, ProKolin paste added to simple food ( Chappie is often recommended, or Hills Low Fat I/d).

But only if vet agrees . (my dog cannot tolerate Chicken & Rice , so I use the Hills)