Ball python poop weight

[tttaylorrr]

Hello,

How do you guys calculate the weight of snake that hasn't pooped yet.
The reason I ask is my female enchi, hasn't pooped and has a sausage butt. She weighed 201 g couple weeks ago and she is at 265 g. Are the poop about the same weight as the prey item she ate? or little less?
I know it is best to weight after empty, but for some balls that hold for a long time, how do you guys calculate/estimate the weight after poop.

probably not what you're looking for but...

post-poop weight
— pre-poop weight
= weight of poop

just did this in the am; Spaghetti left a HUUUUGE poo (and shed)! she was 628g last week, and weighed 599g this am. that was a 30g turd! she eats small rats, which are ~60g, so the poop was maybe half the weight of the feeder.