The story goes that if you do, it will stay in your digestive track for seven years. Is this true?
According to the Mayo Clinic,
Although chewing gum is designed to be chewed and not swallowed, it generally isn't harmful if swallowed. Folklore suggests that swallowed gum sits in your stomach for seven years before it can be digested. But this isn't true. If you swallow gum, it's true that your body can't digest it. But the gum doesn't stay in your stomach. It moves relatively intact through your digestive system and is excreted in your stool.
On rare occasions, large amounts of swallowed gum combined with constipation have blocked intestines in children. It's for this reason that frequent swallowing of chewing gum should be discouraged, especially in children.
The American Chemical Society has a nice video explaining what happens when you swallow gum:
I could have done with this video twenty years ago when a student in the hall I helped supervise was convinced he has gum stuck in his throat and was going to die. He ended up taking himself off to A&E where the staff were not sympathetic.
Constipated? No! As it has a rubber base, if you swallow too much you bounce. But you have to swallow an awful lot.
⬆︎ In logic known as a sillygism.
And if you swallow a bunch of nails, you get a case of irony.