When you swallow a penny or a child swallows a penny the body cannot digest the penny although the Zinc can be eaten away from the penny due to the stomach acid.
Most times a penny will pass through the child's stomach or your stomach in 2 to 4 days and then come out in the poop.
It's usually not a cause for concern or a medical emergency if a child or yourself swallows a penny as long as it's not causing a choking problem.
80 to 90 percent of the time, coins such as pennies will pass unobstructed,
They usually pass in less than four to five days, often within 48 hours." In these cases, you should still consult with your child's doctor or after-hours line immediately.
Although usually nothing to worry about the problem can be that pennies minted since 1982 are mostly zinc and carry only a light coating of copper, which can be eaten away by stomach acid.
The zinc, in turn, can cause lots of problems that include bleeding ulcers and vomiting.
However I can say that the child will likely be just fine because when I was 3 years old I can remember swallowing a penny and nothing happened.
My mom called the doctor and the doctor told her that I should be fine and the penny should just pass through my poop.
It eventually did pass through my poop as my mom was watching my poop when she changed my diapers.
She found the penny in the poop in my diaper the next day when I pooped the diaper.