Green plums are a treat and a delicacy in other cultures. Their sour, bitter flavor can be unappealing and may cause an upset stomach if you are sensitive to sour foods. These fruits are also rich in fiber, which is beneficial for normal digestion. If you do not normally consume enough fiber, eating several green plums may give you a temporary belly ache.
Green plums are unripe fruits about the size of a cherry. They originate from western Asia and have been enjoyed by Asian cultures for centuries. Green plums have a tougher texture and more sour flavor than ripe purple plums. Sprinkling salt or sugar on your green plums helps cut out some of the bitter flavor if it is undesirable for you.
Wash your green plums thoroughly to avoid consuming pesticides, dirt or other contaminants. Each of these may irritate your stomach, causing you to feel some discomfort. Use plain water to clean your fresh fruit. Washing your green plums with soap may leave a residue on the skin of the fruit. Ingesting soapy residue may also aggravate your belly, giving you a stomach ache.
Eating too many green plums increases your fiber intake for the day. Most high-fiber foods provide both soluble and insoluble fiber, although they typically have higher amounts of one over the other. Fresh fruits, like green plums, tend to have higher amounts of soluble fiber. This type of fiber attracts water in your gut and ferments, forming a slow-moving gel. During the fermentation that occurs in your colon, gas is naturally produced, explains Oregon State University's Linus Pauling Institute. Excessive gas in your gut may cause you to feel some discomfort until you pass it. Additionally, too much of either type of fiber may cause constipation or diarrhea. If your diet is normally low in fresh fruits, vegetables and whole-grain foods, slowly increase your intake by a few servings a day as tolerated. Once your body gets used to the fiber boost, you can continue to add more green plums to your diet.
Green plums should not bother your stomach if you are generally healthy. Having a sour stomach after eating a green plum may be a sign of a more serious underlying cause, such as an allergy. Talk with your physician if you notice frequent stomach aches associated with green plums, to rule out any other issues.