i've come to somewhat of a conclusion here, and it's that the colour of the shit seems variable enough for me to conclude that if the low ferritin is due to bleeding then it's not constant. i can't reasonably come to further deductions on the point. is something i'm eating making me bleed short term? is that even possible?
really, i think that, as far as the shit is concerned, i'm looking at two options:
1) it's a parasite and that's why it's sporadic
2) it's just the food and i'm not bleeding at all
that rules it out, but it would almost be easier if i had an ulcer...