National UK audits in inflammatory bowel disease (IBD) highlight a deficit of dietitians in gastroenterology: a priority for improvement supported by national IBD standards

Dietary management of adults with IBD - the emerging role of dietary therapy

Historically, dietitians played a minor part in the management of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis. Patients were commonly referred for consequences of uncontrolled disease, such as malnutrition and bowel obstruction risk. Today, dietitians are fundamental members of the multidisciplinary IBD team, from educating on the role of diet at diagnosis and throughout the lifespan of a patient with IBD to guiding primary induction therapy. This aspect is reflected in published guidelines for IBD management, which previously placed diet as only a minor factor, but now have diet-specific publications. This Review describes a four-step approach in a dietitian's assessment and management of diet in patients with IBD: (1) identifying and correcting nutritional gaps and dietary imbalances; (2) considering diet to treat active disease with the use of exclusive enteral nutrition (EEN) or emerging diets that could replace EEN; (3) using therapeutic diets to control existing complications of IBD, such as reduced fibre to prevent bowel obstruction in stricturing disease or a fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet to manage co-existing functional gut symptoms; and (4) considering the role of diet in preventing IBD development in high-risk populations.

British Dietetic Association evidence-based guidelines for the dietary management of Crohn's disease in adults

BACKGROUND

Crohn's disease is a debilitating chronic inflammatory bowel disease. Appropriate use of diet and nutritional therapy is integral to the overall management strategy of Crohn's disease. The aim was to develop evidence-based guidelines on the dietary management of Crohn's disease in adults.

METHODS

Questions relating to the dietary management of Crohn's disease were developed. These included the roles of enteral nutrition to induce remission, food re-introduction diets to structure food re-introduction and maintain remission, and dietary management of stricturing disease, as well as whether probiotics or prebiotics induce or maintain remission. A comprehensive literature search was conducted and relevant studies from January 1985 to November 2009 were identified using the electronic database search engines CINAHL, Cochrane Library, EMBASE, MEDLINE, Scopus and Web of Science. Evidence statements, recommendations, practical considerations and research recommendations were developed.

RESULTS

Fifteen research papers were critically appraised and the evidence formed the basis of these guidelines. Although corticosteroids appear to be more effective, enteral nutrition (elemental or non-elemental) can be offered as an alternative option to induce disease remission. After a course of enteral nutrition, food re-introduction diets may be useful to structure food re-introduction and help maintain disease remission. Dietary fibre is contraindicated in the presence of strictures as a result of the risk of mechanical obstruction. The use of probiotics and prebiotics is not currently supported.

CONCLUSIONS

As an alternative to corticosteroids, evidence supports enteral nutrition to induce disease remission. Food re-introduction diets provide structure to food re-introduction and help maintain disease remission. These guidelines aim to reduce variation in clinical practice.

Dietary and nutritional considerations for inflammatory bowel disease

Nutritional assessment and dietary advice are fundamental to inflammatory bowel disease (IBD) patient management and all patients should have access to a dietitian. Newly diagnosed patients often think that their pre-illness diet has contributed to the development of their IBD. However, epidemiological evidence to support diet as a risk factor is lacking. How the diet contributes to the gastrointestinal microbiota is interesting, although the role is not yet clearly defined. Nutritional problems in IBD are common. Malnutrition occurs in up to 85% of patients and weight loss affects up to 80% of patients with Crohn's disease and 18-62% of patients with ulcerative colitis. Nutritional deficiencies are prevalent, particularly in relation to anaemia and osteoporosis. Intestinal strictures can be problematic in Crohn's disease and limiting fibrous foods that may cause a mechanical obstruction in the gastrointestinal tract is helpful. Patients often explore dietary exclusion to alleviate symptoms but such changes may be self-directed or inappropriately advised and can lead to further nutritional deficiencies. Some patients experience concurrent functional symptoms (e.g. abdominal bloating, abdominal pain, flatulence and diarrhoea) that can significantly affect quality of life. Recently, a group of poorly absorbed carbohydrates that occur naturally in the diet called fermentable oligo-, di-, mono-saccharides and polyols have been associated with functional symptoms by intestinal bacterial fermentation leading to rapid gas production, and an osmotic effect increasing fluid delivery to the colon. Emerging evidence indicates that a diet low in fermentable oligo-, di-, mono-saccharides and polyols can alleviate functional symptoms in IBD.