Actually, this
https://www.everydayhealth.com/colonoscopy/the-definition-of-a-clear-liquid-diet-for-colonoscopy/
says that I should avoid miso soup.
Some vegetable broths have particles in them which make them unacceptable,
which would probably include the vegetable stock that we already have.
So, yeah, I'll probably need to specifically buy fiber-free bouillon
cubes.
https://www.dietsmealplan.com/food-list/liquid-diet-food-list/ says that
most oils are acceptable, so I'll probably add extra oil to the vegetable
broth / bouillon to stave off hunger.
I guess I can drink coconut water; I think I should buy gatorade if
possible as well, at least to have on hand.