Glass. the question is , how small or sharp is the glass. glass can get lodged in the parts of intestine and cause problems . some times very tiny pieces may not cause any problems and pass out in the stool without complications. seek medical advice for your gp/ER if you have concerns.
It's safe. Most small pieces of glass will pass safely through your intestines. Unless it was 100% glass and a larger piece we wouldn't do an endoscopy. If it happened within 30 minutes and you were in the ER then a doctor could do a bedside scope but we usually don't. Watch for any intestinal bleeding (rare) or severe abdominal pains.