Causes could be parasites (potentially consumed in her prey), or the rate of feeding; there is a finite amount of space in a digestive tract, and a higher rate of feeding means that there needs to be a higher rate of passage of digesta.

This is a very general explanation, but please let me know if I should explain further.

~Rebecca
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3.2 Amazon Tree Boas
1.2 Duméril's Boas
1.0 Boa constrictor imperator
2.6 Ball Pythons

0.2 American Pit Bull Terriers (45lb darling lap dogs: Brandy & Mara)