While oatmeal can help you recover from a bout of diarrhea or irritable bowel syndrome, it can also give you a stomachache.
Oatmeal is a grain commonly eaten as a breakfast cereal or incorporated into cookies, breads, pancakes or waffles. It is rich in carbohydrate and protein, with 1 cup of dry oats delivering nearly 55 grams of carbohydrate and more than 10 grams of protein to your diet. However, oatmeal can cause a stomachache, either because you eat too much of it or because your body has a negative response to a component of the oats. If the oatmeal you eat causes you a stomachache, see a dietician or your health care practitioner.
Stomachache from Indigestion
Almost all the carbohydrate in oatmeal exists as starch. Your body digests starch to its component glucose sugars using amylase, a digestive enzyme secreted by both your salivary glands and your pancreas. If you consume an unusually large volume of oatmeal, the amount of food in your gut may be more than the amylase can keep up with, resulting in a backlog of food in your stomach that can cause a stomachache. This condition, known as indigestion, can persist until your digestive system processes all the oatmeal you ate.
Constipation from Excess Fiber
A cup of dry oats contains more than 8 grams of dietary fiber, supplying roughly one-third of your daily need, according to Linda Boeckner of the University of Nebraska-Lincoln Extension. Important for digestive health, fiber regulates bowel movements and prevents constipation. However, a sudden influx of fiber, or consuming significantly more than you are accustomed to, can actually cause constipation, with symptoms including a stomachache. The high-fiber content of oatmeal, therefore, can result in a stomachache if you take in a large amount of this grain, particularly if you are not used to eating it.
Allergy to Gluten
Food allergy occurs when your body mounts an immune response to a component of the foods you eat. Suppose you have an allergy to gluten. – a plant protein found in certain grains – eating products containing gluten might result in gastrointestinal distress including stomachache. Whether the protein in oatmeal contains gluten is up for debate, according to registered dietitian Susan Mikolaitis. However, oats are commonly processed in the same facility as wheat and can therefore become contaminated with wheat gluten even if the oats themselves do not contain the offending protein. For this reason, oatmeal can cause a stomachache if you have a gluten allergy.
Prevention of Stomachache from Oatmeal
Avoiding a stomachache from oatmeal depends on the reason for your digestive upset. If you ate too much, resulting in indigestion or constipation, cutting back on the volume you consume can help prevent future problems. If your stomachache is due to gluten exposure, you can purchase commercially available pure oats certified to be uncontaminated by wheat gluten. However, since oats themselves may contain gluten, consume them under the direction of a dietitian if you are sensitive to this protein.