[Tinytoes]

Hi and welcome! It might be in his diet. Sweet veggies and anything with sugar can upset a tummy upset. As for the blood, is it bright red, like maybe an irritation in the lining of the large intestine? You might want to take him back to just a basic diet of dried kibble, (Oxbow?) some processed cereals and pumpkin and/or sunflower seeds? Try that for a few days, see if you can isolate the food causing the upset. Rats don't do well with digestive issues, they can't throw up, and gas makes them miserable

 

[Tinytoes]

While you are trying to figure it out, start adding some whole foods. Soft scrambled eggs and cooked white rice. Oatmeal. Cream of wheat. Just like you would with a dog who is having digestive issues. Poop eating is actually normal, they get digestive enzymes that help with their gut. I wouldn't worry about that, but if he's doing it a lot, then like @Enne said, he may be deficient in some nutrients.

 

[Tinytoes]

Hi there.
You mentioned you were fasting him for 24 hours at a time to give his tummy a break.
I would recommend against this, or at least maybe for a shorter time frame, as pet rats aren't supposed to go without food for long. This is why when they have an anaesthetic, you don't with-hold food like you would for a cat or dog. Partly because they can't vomit anyway, and partly because they have such a high metabolism that they need to be constantly eating, so they don't use up their own reserves. That's what I remember reading a while back, anyway. Hope this helps.

Yes to the not fasting. Rats can get low blood sugar, especially after surgery which is why we feed them, and keep food in the carrier for them afterwards. At this point, the little guy needs his calories, but also not to have the runs and get dehydrated.

 

[Tinytoes]

I'm so sorry to hear, thanks for letting us know. You tried so hard with your little guy. Sometimes their fate is out of our control.