I don't go by the poop method as each snake poops differently. My guideline is anything up to 1 year old, I feed once a week. Then from 1-3 years, every 2 weeks. After 3 years old, if its a male, then once a 3-4 weeks. If its a female, once every 2-3 weeks. But those are guidelines. You also play it by sight. If your boa is starting to look chunky, back off the food. If its constantly hunting for food, then maybe feed it a bigger meal.

Also some people will quit feeding them in the winter to mimic the wild. That works fine too but me personally I just feed them the same but might extend out the feeding a little in the winter but generally the same.