If anything prevents carbohydrates from being broken down or passing through the lining of the small intestine, they cannot be absorbed, and malabsorption is said to occur. There are many possible causes of malabsorption, among them:
- Lack, or shortage, of the necessary digestive enzymes. This is a common cause of lactose (milk sugar) malabsorption in adults.
- Fast intestinal transit time; food is catapulted through your system without enough time for digestive enzymes to work.
- Total amount of sugar in the meal exceeds the capacity of the small intestine to digest and absorb it.
- Composition of the meal; fructose is absorbed more completely in the presence of glucose and less completely in the presence of sugar alcohols.
- Damage to the lining of the small intestine, for example, from food poisoning, a virus, untreated celiac disease or Crohn's disease.
- Short bowel syndrome; if any length of the small intestine has been surgically removed, malabsorption can occur.
- Some carbohydrates, the dietary fibers such as those found in wheat bran or beans, are never digested or absorbed in the small intestine. Humans do not have the digestive enzymes to break down these dietary fibers.
When carbohydrates are malabsorbed, they pass to the end of the small intestine and into the large intestine.
Find out more about this book:IBS: Free at Last! Change Your Carbs, Change Your Life with the FODMAP Elimination Diet, 2nd Edition