Gastrointestinal Disorders

The gastrointestinal tract includes the small and large intestine. It is a large and complex organ that plays a vital role in maintaining good health. The main function of the gastrointestinal tract is to digest and absorb nutrients from the food you eat. It supports a large and diverse community of bacteria and contributes to keeping your immune system healthy. There are many different gastrointestinal disorders which affect normal functioning of the gastrointestinal tract. Some of these disorders include irritable bowel syndrome, inflammatory bowel disease and coeliac disease will be discussed in more detail below.

Irritable bowel syndrome (IBS)

IBS is a common functional gastrointestinal disorder. It is commonly characterised by the following gastrointestinal symptoms:

  • Distention and bloating
  • Excess wind
  • Lower abdominal pain
  • Altered bowel habits (diarrhoea and/or constipation or a combination of both).

These symptoms can cause stress and anxiety, may compromise everyday life and may interfere with busy schedules. It is important to be aware that these symptoms also overlap with several other serious gastrointestinal and gynaecological conditions such as inflammatory bowel disease, coeliac disease and endometriosis and bowel cancer. Therefore, these symptoms should be discussed with a medical practitioner before you make any dietary changes.

Current research investigating the diet and IBS symptoms focuses on a large group of fermentable sugars in the diet, known as FODMAPs (Fermentable, Oligosaccarides, Disaccarides, Monosaccarides and Polyols). Evidence suggests that FODMAPs can trigger IBS symptoms. FODMAPs are poorly absorbed in the small intestine and continue along the gastrointestinal tract to the large intestine where they are fermented by bacteria which produces gas. Gas production can lead to wind, bloating, discomfort and abdominal pain. Furthermore, FODMAPs also draw fluid into the gut which can alter the movement of gastrointestinal contents and may contribute to diarrhoea and/or constipation.

The low FODMAPs diet is a therapeutic, evidence-based diet designed by Dr Sue Shepherd and Dr Peter Gibson. The diet involves eliminating foods high in FODMAPs from your diet for a period of 6weeks until symptoms settle. During your initial dietitian consultation, you will be provided with information about the low FODMAPs diet and foods to avoid and consume. Nutrition support will be provided to ensure that your low FODMAPs diet is nutritionally adequate as certain nutrients are at risk while following the low FODMAPs diet. These include calcium, B vitamins and fibre. After your symptoms settle, foods containing FODMAPs can be challenged through a reintroduction protocol which will be discussed in detail during your follow up dietitian appointments. In the long term, this will ensure that you are following the least restrictive diet to maintain symptom control.

Inflammatory bowel disease (IBD)

IBD is used to describe two diseases that cause inflammation of the bowel wall, Crohn’s disease and Ulcerative colitis. Ulcerative colitis causes inflammation of the lining of the colon and rectum, whereas Crohn’s disease causes inflammation of the full thickness of the bowel wall and can occur anywhere along the gastrointestinal tract. Although there is no evidence that diet causes the development of IBD or flare ups of the disease, diet does play a role in reducing some of the symptoms associated with IBD and is important to prevent malnutrition and to maintain a healthy weight. IBD can be active and inactive over periods of time. When the disease is not active, it is important to follow a healthy, balanced diet. In contrast, during a flare up or where symptoms increase in severity, you may find that certain foods aggravate your symptoms, therefore, following a low fibre diet can help your symptoms settle. Information about following a healthy, balanced diet and how to manage flare ups will be covered during your dietitian consultations.

Coeliac Disease

Coeliac disease is an autoimmune disease where the body experiences an abnormal reaction to gluten, a protein found in wheat, rye and barley. A similar protein is found in oats and causes the same abnormal reaction. Exposure to gluten causes inflammation of the small intestine and the body mistakenly produces antibodies which damage its own tissues. This leads to breakdown of tiny projections which line the small intestine called villi. Villi are sites of nutrient absorption, therefore, exposure to gluten leads to nutrient malabsorption. The symptoms of coeliac disease include:

  • Distention and bloating
  • Excess wind
  • Lower abdominal pain
  • Altered bowel habits (diarrhoea and/or constipation or a combination of both
  • Fatigue
  • Iron/folate deficiency
  • osteoporosis

Certain genes are associated with Coeliac disease and the disease is hereditary. If you experience any of the symptoms of Coeliac disease and/or have a family history, it is important to get screened. The tests for Coeliac disease include a gluten challenge, blood tests and a small bowel biopsy to confirm diagnosis. It is important to be tested for coeliac disease before trying a gluten-free diet. This is because eliminating gluten from your diet may change the results of the tests used to confirm diagnosis of Coeliac disease.

Your doctor can order two initial blood tests to screen for Coeliac Disease. If test results indicate Coeliac disease, you will be referred to have an endoscopy to view your small intestine. During the endoscopy, a small tissue sample (biopsy) will be taken to analyse for damage to the tissue. A small biopsy is essential to confirm a diagnosis of Coeliac Disease. The diagnosis can only be made if atypical small bowel changes associated with Coeliac disease (villous atrophy) are observed.

Coeliac disease can develop at any stage in life, you may be born with it or you can develop it later in life. Although researchers are currently working on a vaccine for coeliac disease, currently the only effective way to manage the disease is to follow a strict, lifelong gluten free diet. The risks of leaving Coeliac Disease untreated include:

  • osteoporosis
  • suboptimal nutrient absorption of calcium, iron, vitamin B12 and vitamin D in particular
  • mouth ulcers
  • infertility
  • liver disorders
  • dental enamel defects
  • increased incidence of bowel cancer

If you have been diagnosed with Coeliac Disease, your initial dietitian consultation will involve discussing the gluten free diet in detail. Your Dietitian will provide individualised dietary advice to ensure that you are not at risk of any nutritional deficiencies while following the gluten free diet. Furthermore, education will be provided about label reading and cross contamination. Strategies for eating out will also be covered.