Get fiber supplements in pill form

Fiber gummies are easy to pack.. there are also sandwich wraps you can buy that lay flat in a plastic wrapper that are like 8-10 grams each ( read the labels not all are the same) and 3 days before you go All Bran so you at least start off good..the rest of the stuff will just be so you can maintain

You can take dried fruit (packaged prunes, dates, etc). You could also take ground flax seed - that is my go to solution to constipation.

Do they drink mate in the region you are going to? That may work to promote efficient elimination!

I was in Chile more than a decade ago but I am sure I would still remember not having access to coffee or tea, since that would have been a crisis. We were backpacking in Patagonia so definitely remote at some points ... but the grocery store in Puerto Natales where we bought provisions, and the corner stores in other spots, certainly had coffee.