Bezoar

A bezoar is a hard ball made of pieces of things that get stuck in your stomach. Imagine eating a bunch of hair or fur - that's gross, right? But sometimes animals (and even people) like to chew on things they shouldn't. When you swallow those things, they can get stuck in your stomach and lump together into a hard ball that won't go away on its own.

Bezoars can be really dangerous because they can block your stomach from emptying properly. This can make you feel really sick and even cause you to throw up. Doctors can remove bezoars in a few different ways, depending on what they're made of and how big they are. Sometimes they can use endoscopes (a tool with a tiny camera and other instruments) to reach into your stomach and grab the bezoar. Other times, surgery might be necessary to remove it. Either way, it's important to get a bezoar treated so that it doesn't cause more serious problems for your tummy.