If your stomach "exploded" you would definitely know it. I have never heard of a stomach exploding before but if yours did you would know IMMEDIATELY. Severe pain, vomiting, and internal bleeding from all that acid entering the rest of your body. But trust me: your stomach won't explode from overeating or stretching. You may pull a muscle or vomit ( I have vomited from eating too much) but if our stomach can handle all that acid and abuse we put through it I doubt it would explode from stretching.