According to the search results, drinking Coke and eating Mentos at the same time is an urban myth. The reaction that occurs when Mentos are put into a bottle of Coke is caused by the rough coating of the candy, which results in lots of bubbles forming rapidly on the surface when it’s placed in a carbonated beverage. However, the coating begins to dissolve the moment you eat it, so you won’t get the same reaction in your stomach.

If you drink Coke right after eating Mentos, the reaction is almost negligible because the act of pouring the soda in your mouth releases so much of the pressure and carbonation that by the time it touches the Mentos youve eaten, the reaction is almost negligible. Youd have to swallow the Mentos whole and then put a tube down your throat and pour the soda straight into your stomach for it to react, and all that would really do is make you belch heavily and maybe regurgitate some of it.

While drinking Coca-Cola and swallowing Mentos will make you feel sick, it will not cause your stomach to explode. You may vomit up frothy Coca-Cola in a fairly violent fashion, but only for a few seconds each time. In fact, you may do untold damage to your stomach. Therefore, it is not recommended to eat Mentos and drink Coke at the same time.