Many toys have button batteries in them, so children eating button batteries happens from time to time. Button batteries contain corrosive acidic or alkaline substances. If a child accidentally ingests a button battery, he or she should be taken to the hospital for an X-ray examination as soon as possible to determine where the coin is lodged in the digestive tract. If the battery is stuck in the esophagus or throat, urgent endoscopic treatment is required. This is because once the battery casing breaks it can leak corrosive substances that can cause severe burns, transmural erosion, fistula formation, etc. in the esophagus, and later can cause esophageal scarring and stricture. If the battery is located below the esophagus, it is not necessary to remove it unless there are signs and symptoms of gastrointestinal damage or repeated X-rays show that a larger battery (greater than 20 mm in diameter) has remained in the stomach for more than 48 hours. Once the battery has passed through the pylorus into the duodenum, 85% will pass through the pylorus in less than 72 hours, in which case X-rays every 3-4 days are appropriate.