Specific foods can reduce symptoms of irritable bowel syndrome and functional constipation: a review

Functional gastrointestinal disorders (FGIDs) are groups of disorders involving digestive symptoms that chronically persist despite the absence of organic abnormalities in the gastrointestinal tract. Representative FGIDs include functional dyspepsia (FD), irritable bowel syndrome (IBS), and functional constipation (FC). In particular, IBS is a disease representative of FGIDs in which abdominal pain and discomfort associated with abnormal bowel movements chronically persist and recur. These symptoms are known to be related to lifestyle habits, such as meals and stress. In recent years, according to advances in dietary therapy for IBS and FC, specific foods have been shown to alter these symptoms. In IBS, bowel movement abnormalities and abdominal discomfort have been reported to be reduced when patients eat these specific foods.

Several studies suggest that individuals with certain attitudes toward eating or with preferences for fatty food, fast food, junk snack food, fried food, and hot/spicy food showed a higher prevalence of gastrointestinal (GI) symptoms. Those who are cognizant of nutritional balance or healthy food intake have a lower prevalence of GI symptoms. Thus, eating specific foods with higher dietary fiber and low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharaides, and polyols) is effective for relief from some GI symptoms.

First, two kinds of dietary fibers are found in foods: water-soluble dietary fiber and insoluble dietary fiber. Enduring misconceptions about the physical effects of fiber in the gut have led to misunderstandings about the health benefits attributable to insoluble and soluble fiber. Previous reviews suggest that health benefits have been shown in regard to fiber, and reproducible evidence of clinical efficacy has been published.

Second, the ingestion of certain carbohydrates causes gastrointestinal symptoms. Foods rich in fermentable oligosaccharides, disaccharides, monosaccharaides, and polyols (collectively known as FODMAP) have been shown to cause abdominal pain and abdominal discomfort in westerners with IBS.

Dietary therapy for FGIDs should include specific foods that have been scientifically proven to be effective for managing symptoms of irritable bowel syndrome and functional constipation.