If you don't typically include an adequate amount of fiber in your diet, then suddenly increase your intake, you may experience stomach pain, gas and bloating. Your body will soon adjust, though, and the symptoms should subside. If you continue to experience stomach pain after eating high-fiber foods, you should speak with a doctor. Some digestive system conditions can cause stomach pain from eating certain types of fiber or high-fiber foods.
Definition
Fiber is the portion of a plant-derived food source that your body isn't able to digest or absorb into the blood stream. Because fiber is indigestible, it adds bulk to your stool and helps maintain regularity. Fiber is classified into two categories: soluble and insoluble. Soluble fiber dissolves in water and turns to a gel in the digestive system. It is commonly found in peas, beans and oats, regulates digestion, and lowers cholesterol and glucose levels. Insoluble fiber is roughage that increases stool bulk, pushing it through the digestive system. This type of fiber is found in wheat bran, nuts and certain vegetables.
What Fiber Does
A diet low in fiber will often result in constipation, which can contribute to hemorrhoids or diverticula; that is, small pouches in the colon. Dietary fiber helps prevent constipation and its complications, is associated with lower cardiovascular risks and, because it is filling, can promote weight loss. If you plan to increase your fiber intake, you should do so slowly, over the span of several weeks. Suddenly adding high-fiber foods to the diet or taking a fiber supplement can overwhelm the bacteria in your intestine, resulting in excessive gas, bloating and stomach pain. This effects usually end once the bacteria become accustomed to the increased fiber.
Considerations: Medical Conditions
With certain digestive conditions, eating fiber can cause stomach pain. Irritable bowel syndrome, or IBS, is a common digestive condition that produces chronic diarrhea or constipation, along with stomach pain, bloating and cramping. Some fruits and vegetables high in fiber may trigger IBS symptoms. Crohn's disease is an inflammatory bowel condition that causes abdominal pain and diarrhea. Fiber can sometimes exacerbate the stomach pain, gas and diarrhea of Crohn's disease. Celiac disease results in stomach pain and diarrhea when those who have it eat the protein gluten. Because gluten is found in wheat, barley and rye, some high-fiber foods, like bran muffins and whole-wheat pastas and breads, can make celiac symptoms flare.
Solutions
Always increase the fiber in your diet gradually, giving your body several weeks to adjust to the change. Drink ample fluids -- at least eight glasses of water or other non-caloric liquid -- throughout the day to help the fiber pass through your digestive system. If you have a medical condition you suspect might be worsened by certain types of fiber or fibrous foods, talk with your doctor. He can provide information on the most effective solutions specific to your situation.
