I had stomach pain with Cryptolepis for sure. I have a lot of pollen/plant allergies so not sure if it is related to that.
I can tolerate 3-drug antibiotic regimen with lots of pills without any problem like the Cryptolepis caused.
Resveratrol causes IBS diarrhea symptoms for me. Japanese Knotweed contains resveratrol, so that could be a potential culprit for you.
So I just started on the cryptolepis and I have a dull ache in my stomach and just fatigued. I didn't know what it was.
Perhaps it's that?