We have a 16 year old female cat with diarrhea. She has it all the time, it never ends and has been going on for months. The vet said after her blood test that she may have liver disease or liver cancer. She was given medication for liver disease. She has not gotten better. She still has the runs. We have changed her food around but have mainly fed her stuff bought at the local grocery. She is constantly starving and always wants to be fed and then poops it right out. She going around the house meoing as though she is in pain or distress yet she still purrs. We have lost two other cats over the last year or two. I know she is also mourning their loss. Like I said she is always hungry, begging and always has the runs and seems to drink alot of water. Does anybody know what may be wrong?