Irritable Bowel and Crohn's Disease

Crohn’s disease is a chronic disease characterized by patchy inflammation of the intestines and relapsing and remitting symptoms. Crohn’s disease and other IBs are increasing worldwide, with the highest rates seen in young adults of Europe and North America.1 Crohn's disease mostly impacts the small and large intestines, but can affect other areas along the GI tract anywhere from the mouth to the anus.

The intestinal inflammation of Crohn’s disease is driven by an altered immune response that activates nuclear factor (NF)-κB, tumor necrosis factor (TNF)-alpha, and pro-inflammatory cytokines.2 Numerous genes and polymorphisms have been associated with Crohn’s disease, but environmental signals are thought to play a key role in triggering disease onset.3

Symptoms and diagnosis of Crohn's disease
The GI Tract

Symptoms of Crohn’s disease vary for individuals, from mild to severe, from annoying to debilitating and from chronic to sporadic.

Symptoms can include diarrhea, fever and fatigue, abdominal pain, cramping, blood in the stool, mouth sores, reduced appetite, and weight loss. Symptoms may manifest outside of the GI system as well.

Environmental factors that may contribute to the development of Crohn’s disease include smoking, high intake of nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptive use, vitamin D deficiency, high-carbohydrate and low-fiber diet, lack of exercise, sleep disturbances, and major life stressors.4 These environmental influences are thought to trigger disease via mechanisms that compromise intestinal barrier function and disrupt the intestinal microbiome. Indeed, genomic studies confirm consistently low numbers of Firmicutes, Bifidobacteria, and Lactobacilli, and high numbers of Escherichia coli and other strains of Enterobacteriae in patients with Crohn’s disease.5

Diagnosis is often made by a gastrointestinal specialist after extensive testing including various blood tests evaluating minerals, and red and white blood cell counts and more, as well as through performance of an endoscopy, barium x-rays, CT scans, or a colonoscopy

An elemental diet (including Physicians’ Elemental Diet) is not intended to cure or comprehensively treat all symptoms of Crohn's Disease or replace standard medical care. 

There is no "treatment" of Crohn's disease, it is a chronic condition and as such, the plan of care is focused on management, namely achieving and maintaining remission.

As such, there is no standard protocol for the management of Crohn’s due to the individualization of symptoms and complexities of the disease. Biologic agents have revolutionized the management of IB, by their ability to induce remission and change the natural course of the disease.6 But these medications have serious adverse effects and do not help all patients. There are defined categories of medications used including aminosalicylates, corticosteroids, immunomodulators, antibiotics, and biologic therapies. Being on one, or several, medications is not uncommon. Depending on severity and effectiveness of these medications, surgery is also common.

Patients, clinicians, and researchers are turning to the elemental diet for the dietary management of Crohn’s Disease.

An elemental diet (including Physicians’ Elemental Diet) is not intended to cure or comprehensively treat all symptoms of Crohn's Disease or replace standard medical care. 

Management of Crohn's Disease
Nutrition and Diet Implications

Nutrition is vital to patients with irritable bowel and Crohn's. The small intestine plays the most significant role in the absorption of nutrients. When it is not functioning optimally, nutrients cannot be properly absorbed. Many patients also find that certain foods trigger symptoms and often change their diet to avoid the negative consequences. There is not a specified or proven diet regimen for patients with Crohn's; however, due to how vital it is to maintain fluids and the right level of nutrients, individualized nutritional intervention or counseling is often recommended.

The elemental diet is a medically supervised, sole nutrition dietary management given to individuals with moderate to severe impaired gastrointestinal function for 14-21 days.

The diet consists of macronutrients broken down into their elemental form requiring little to no digestive functionality allowing time for the gut to rest. Elemental formulations are believed to be entirely absorbed within the first few feet of small intestine.7

Products designed for the Elemental Diet contain anywhere from 14-18% of calories from protein in the form of amino acids, 42-76% calories from carbohydrate in the form of monosaccharaides, and 6-43% of calories from fat in the form of fatty acids. The micronutrient composition of an elemental diet is tricky because it must be sufficient for up to 3 weeks, but not exceed safe levels of ingestion even for impaired individuals. When an elemental diet is determined to be the next step for an individual, the patient’s caloric need is first determined. During this time no other foods are consumed other than the medical food and water. Elemental diets can also be implemented as half or partial elemental diet for patients with Crohn's and partial whole food as long as caloric needs are maintained. After the elemental diet is complete, a reintroduction and assessment of foods is conducted.

Elemental Diet for Crohn's Disease
  1. Ye Y, Pang Z, Chen W, Ju S, Zhou C. The epidemiology and risk factors of inflammatory bowel disease. Int J Clin Exp Med. 2015;8(12):22529-42.
  2. Manuc TE, Manuc MM, Diculescu MM. Recent insights into the molecular pathogenesis of Crohn’s disease: a review of emerging therapeutic targets. Clin Exp Gastroenterol. 2016;959-70.
  3. Barrett JC, Hansoul S, Nicolae DL, et al. Genome-wide association defines more than 30 distinct susceptibility loci for Crohn’s disease. Nat Genet. 2008;40(8):955-62.
  4. Legaki E, Gazouli M. Influence of environmental factors in the development of inflammatory bowel diseases. World J Gastrointest Pharmacol Ther. 2016;7(1):112-25.
  5. Bosca-Watts MM, Tosca J, Anton R, et al. Pathogenesis of Crohn’s disease: Bug or no bug. World J Gastrointest Pathophysiol. 2015;6(1):1-12.
  6. Kawalec P, Mikrut A, Wiśniewska N, Pilc A. Tumor necrosis factor-α antibodies (infliximab, adalimumab and certolizumab) in Crohn’s disease: systematic review and meta-analysis. Arch Med Sci. 2013;9(5):765-79.
  7. Pimentel M, Constantino T, Kong Y, Bajwa M, Rezaei A, Park S. A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Digestive Diseases And Sciences. 2004;49(1):73-7.