HI Tiff,
I just wanted to say that I had my little Jomo, a rescue kitty, for nearly 4 years and she suffered from chronic pancreatitis. She would go through periods of time where she was insatiable. She would eat, and eat and eat. She would eat whatever I would put in front of her, AS LONG AS it had about (1)TBS of water added to it.
For awhile, I was giving her that vet prescribed pork pancreatic enzyme because I had read online that if the cats poop is of a light color it means that their body is not absorbing the nutrients and they will be constantly hungry. That enzyme helped FOR A LONG TIME. She got very healthy and strong again. And then, all of a sudden, she was barfing and sick again. Then I would take her off of it and we would start the entire rounds again.
Jomo also pooped a lot. I DID put baby food squash in her food every time she ate although she never had diarrhea the entire time she was with me. I had read somewhere that pumpkin helped with pancreatitis. She didn't like pumpkin but she didn't mind the baby food squash.
Anyway, she would get that type of insatiable hunger just before she was going to have an 'episode' where I would have to take her to the vet for a few days for IV fluids. I knew how to give fluids but when the vomiting would come too often there was just no way I could keep enough fluids in her by giving them to her myself.
I always suspect pancreatitis for nearly everything wrong with a cat. It goes too often undiagnosed and not recognized in cats too often. It is very painful for cats as well as for humans. That is one reason why the cry so much.
Also, the vets killed my Jomo. She was having a P episode and they thought for sure that she SHOULD be a diabetic although none of her BG numbers while she was in the hospital were ever high. She was always normal. I had never ever taken her BG before. I knew nothing about diabetes at that time. They asked me if they could give her an insulin to see if that would make her feel better. I trusted the vets, what did I know? They gave her the shot. I brought her home and I knew immediately that something wasn't right. She began drinking too much water right away and she had never done that, ever.. By morning she was making the most God-awful howling I had ever heard in my life and she was staggering. I picked her up and rushed her to the emergency room where they demanded that I put her to sleep because she was in too much pain.
I later researched those symptoms and learned that howling, staggering, and unbalance like that was a symptom of a hypo attack.
Another very simple reason for lots of meowing to treat is intestinal worms. Worms are not always easy to find in a cat's stool. Is your cat and indoor/outdoor cat?