Inflammatory Bowel Disease

Inflammatory Bowel Disease is a general term used to refer to inflammatory diseases of the bowel. There are two primary forms of inflammatory bowel disease, Crohn’s disease and ulcerative colitis. The disease can be mild and episodic or severe and chronic.

Both Crohn’s and ulcerative colitis present the same symptoms such as abdominal pain, diarrhea, and fever. What distinguishes Chron's diesese and ulcerative colitis is where they occur in the intestine.

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Crohn’s disease can involve the inflammation of any part of the gastrointestinal tract; mainly the distal ileum and colon. Chron's disease also affects segments of the tract and many layers of the intestinal wall. Fistulas can form and when healed segments of these fistulas are replaced with fibrotic tissue, destroying the intestine’s ability to perform its primary function. A biopsy is hard to evaluate in Chron's disease as diseased segments alternate with healthy segments thus a sample of healthy segment could be analyzed instead of a diseased one.

What is Crohn's Disease?

Ulcerative colitis begins in the rectum and progresses to the large intestine, it is continuous and only involves the mucosa (outermost layer of the tract’s lumen).

What is Ulcerative colitis?


Both men and women are equally affected by the disease which often occurrs between the ages 15 and 30. Although the actual etiology is unknown, it is believed to be triggered by environmental factors, such as smoking, infectious agents and the intestinal flora, with a strong genetic association. The genetic makeup of the individual dictates the risk and characteristics of the disease. Genetic diversity explains the difference between onset, aggressiveness, complications, locations, and responsiveness to treatment found in patients. It has also been found that the GI flora play a major role. The immune response provided in ulcerative colitis patients' flora is inappropriate causing an inflammatory response that cannot be suppressed, causing IBD. We then see a response at themolecular level such as the increase of cytokines and oxygen radicals are what damages the intestinal walls.

The individual suffering from IBD must be careful of their diet as it can trigger relapses; foods, microbes, specific nutrients, and contaminants can provide potential antigens for the gut flora immune response to be enhanced. Food intolerances may occur in people suffering from IBD but there is no direct relationship yet detected in studies.

Symptoms of IBD

Common symptoms of IBD include:

  • Abdominal discomfort
    • Cramping
    • Pain
  • Altered intestinal mobility
  • Feeling bloated
  • Diarrhea
  • Constipation
  • Gas
  • Straining or increased urgency to defecate
  • Mucus in stool

Signs of IBD

To be diagnosed with IBD a pateint must have abdominal pain and discomfort for any 12 weeks out of the year and present with two of the following symptoms as well:

  • Chang in frequency or consistency in stool
  • Mucus in stool
  • Bloating or abdominal distention
  • Straining or increased urgency to defecate or a lack of feeling of completely emptying the bowels

Treatment of IBD

The treatments for IBD vary from patient to patient and vary with severity as illustrated in the picture below.

Medical Therapy for IBD

The main goals of the treatment of IBD are to induce and maintain remission and to improve nutrition status. Most therapies treat IBD by attempting to regulate the inflammatory response. The most commonly used treatment agents are corticosteroids, anti-inflammatory agents, immunosuppressive agents, antibiotics, and monoclonal antitumor necrosis factor or anti-TNF. Anti-TNF is an agent that inactivates one of the primary inflammatory cytokines and is typically only used in the most severe cases of Crohn’s disease, as it has not been shown to be effective in the treatment of ulcerative colitis.

Surgical Management of IBD

Often, surgical intervention may be necessary to repair strictures or to remove sections of the bowel when drug therapies fail to lower the inflammatory response.

Crohn’s Disease

Between 50%-70% of Crohn’s disease patients will require disease related surgery to remove the affected portions of the bowel at some point. However, surgery does not cure the disease, as many patients often experience a recurrence of the disease within 3 years and 30%-70% of surgery patients will require additional surgery. Surgical management of Crohn’s disease can often lead to malabsorption of fluids and some nutrients due to the reduction in absorptive area.

Ulcerative Colitis

Surgical intervention is far less likely for patients suffering from ulcerative colitis. About 20% of patients require surgical removal of the entire colon. However, unlike Crohn’s, surgical removal of the colon completely resolves ulcerative colitis.

Nutrition Therapy for IBD

The first and most important step in the nutritional therapy for IBD is ensuring adequate caloric and protein intake. This can be supplemented with tube feedings if oral intake is not meeting calorie needs, especially in children. Also, medium chain triglyceride, or MCT, oil may be supplemented in the diet by adding to sauces or dressings in order to boost calorie intake. MCT oil may be better tolerated than traditional fatty acid sources as it is easier to absorb.

If fistulas or strictures are present, a low fiber and high energy diet would be best tolerated.

Each individual is different and not every diet will work the same in controlling disease symptoms in every patient. Therefore, each person suffering from IBD should work with their medical professional to experiment and find a diet that best controls their own symptoms and provides for their nutritional needs.

Inflammatory Bowel Disease Overview

Other IBD Resources:

Mayo Clinic
American Gastroenterological Association
Crohn's & Colitis Foundation of America


Mahan, L.K. and Stump, S.E. Krause's Food and Nutrition Therapy. (2008). Canada: Saunders Elsevier. p. 689 - 692

Crohn's Disease vs Ulcerative Colitis: IBD. (2010). Retrieved from:

Mayo Clinic staff. (2011, July 29). Tests and diagnosis. In Mayo Clinic. Retrieved April 22, 2012, from

Ulcerative Colitis Health Center. (2011). Retrieved from: