Everything has a battery these days - even toys for kids.  That's why it should be no surprise that Emergency Room visits for kids that have swallowed batteries have increased.  A recent report shows that these sort of ER visits have more than doubled over the last two decades.

Besides the obvious concerns, many of today's "button-style" batteries pose potential problems with the child's digestive tract.

[I]f kids swallow them, they can become lodged in the esophagus and start an electrical current flowing through the tissue -- without kids showing any signs of immediate injury.

"If a child swallows a button battery, the parent might not see it happen and the child might not have symptoms initially -- and the clock is ticking," said Dr. Gary Smith, head of the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus, Ohio and one of the authors on the new study.

"We've seen children in less than two hours have severe, severe injuries from button batteries getting caught in the esophagus," he told Reuters Health.

Experts say that the increase is more than likely caused by the evolution of battery-types that are found in the home.  Twenty years ago, most batteries were the more "standard"-style AA or AAA or even D-cell batteries;  "Button-style" batteries are more commonly found these days in everything from hearing aids and remote controls to children's toys.