Inflammatory Bowel Disease(s) (IBD) and Irritable Bowel Syndrome (IBS)
Updated: Apr 19
Approximately 1.3% of United States (US) adults reported having an Inflammatory Bowel Disease (IBD) in 2015, and the prevalence of IBD is increasing. IBD is a disease of the digestive system (primarily located in the intestines) that causes inflammation and results in undesirable symptoms such as abdominal pain, fatigue, rectal bleeding, and weight loss. There are two common types of IBD: Chron’s Disease (CD) and Ulcerative Colitis (UC). Inflammatory Bowel Diseases differ from Irritable Bowel Syndrome (A condition with the similar abbreviation and similar symptoms). People experiencing any of these conditions will benefit from working with a dietitian in addition to their doctor.

CD is primarily affects the small intestine and beginning of the large intestine, but can spread to any part of digestive tract typically occurring in early adult hood. The symptoms of CD begin gradually and often get worse over time. People affected by CD typically experience periods of flare ups and remissions. Symptoms include intestinal obstruction, fistulas, abscesses, fissures, and ulcers inside the GI tract. As a result, many people with CD experience malnutrition due to the inability to comfortably consume nutritious foods. Treatment may include steroids, aminoslicylates, immunomodulators, biologic therapies, periods of bowel rest, surgeries, and diet. During periods of flare up: small meals with high calories and adequate hydration are essential, while foods high in fiber, fat, salt, and lactose should be avoided. During periods of remission, individuals should aim to consume a balance diet rich in fiber foods.
Like CD, UC also causes inflammation throughout the digestive tract; however, the inflammation is primarily isolated in the lining of the large intestine and is a result of the body’s immune response. People with UC experience periods of flare up and remission like CD. The symptoms, related complications, and forms of treatment are similar to that of CD. A healthy and well-balance diet is recommended for people with UC. Additionally, recommendations for eating during a flare up and a remission period vary and fall in line with the same recommendations as for those with CD.

According to studies, about 12% of the US population has Irritable Bowel Syndrome (IBS). IBS is a functional gastrointestinal (GI) disorder, meaning that the function and movement of the GI tract is affected. GI dysfunction results in abdominal discomfort/pain, bloating, and changes in bowel movements. People with IBS fall under 1 of 3 categories: IBS-Constipation (IBS-C), IBS-Diarrhea (IBS-D), or IBS-Mixed Bowel Habits (IBS-M). A diet with adequate fiber-rich foods has been found to assist with normalizing bowel movements and reducing GI discomfort in those with IBS. Additionally, elimination diets (such as the FODMAP) are a great way to isolate the food(s) responsible for IBS symptoms.
IBD and IBS are increasingly prevalent. Both conditions have unique etiologies; however, some of their symptoms overlap. Anyone affected by IBD and/or IBS will benefit from working with a doctor and dietitian. If you have questions or want to learn more about IBD or IBS, please reach out!