Add Yahoo as a preferred source to see more of our stories on Google. Your small intestine is lined with tiny protrusions called villi that play a big role in digestion. Sebastian Kaulitzki/Science ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. How does your body make poop? Owen, 4, Wakefield ...

Brian Robert Boulay does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations ...