I have more 2 recommendations that might work (from my vet):
"1. See his vet for a senior profile bloodwork panel and thorough physical exam. The blood work will tell you how the kidney and liver are doing along with how his blood cells are doing. Kidney disease causes anemia.
2. You can try...
I have a pregnant cat she should be due any day now, she has crusty milk discharge, but today I noticed a clear liquid coming out in very small amounts when presure is added to the area, should I be conserned?
If your kitten does get diarrhea and you want to try a home remedy, you can try adding a little canned pumpkin to their food. The pumpkin increases the fiber in their diet and can balance out their GI tract. A powdered fiber supplement can also be mixed into their food.
Have you tried this already?