The main reason for stomach upset after eating pineapple is that pineapple contains a lot of acid, which is likely to stimulate excessive secretion of stomach acid, thus causing stomach upset. Pineapple is a cold food that is not easy to digest, so if you eat too much of it, it will not be conducive to digestion and may lead to stomach cold. For patients suffering from gastroenteritis, gastric ulcer, chronic colitis and other digestive disorders, after excessive consumption of pineapple, indigestion, stomach pain, acid reflux will be further aggravated, stomach discomfort will be more obvious. If you are suffering from digestive system diseases, usually try to eat as little as possible pineapple and other cold food. For normal people usually in the consumption of pineapple, should also pay attention to should be eaten in moderation. If you have an upset stomach after eating pineapple, you can seek medical help in time.