Irritable bowel syndrome


IMPORTANT The information provided is of a general nature and should not be used as a substitute for professional advice. If you think you may suffer from an allergic or other disease that requires attention, you should discuss it with your family doctor. The content of the information articles and all illustrations on this website remains the intellectual property of Dr Raymond Mullins and cannot be reproduced without written permission.

Last reviewed 5 June 2020

What is irritable bowel?
Irritable Bowel Syndrome effects the small and large bowel. Common symptoms are loose bowel motions, constipation, cramps, wind and bloating. While uncomfortable, irritable bowel is not dangerous and does not decrease life span. Irritable bowel is diagnosed when no other cause can be found for these symptoms, such as an ulcer, celiac disease, lactose intolerance (milk sugar intolerance), fructose intolerance (fruit sugar intolerance) or inflammation in the bowel.

Danger signs
Those with recent onset symptoms, changes in bowel habit or blood or weight should be investigated for an underlying disorder first before diet manipulation is considered. Always check for celiac disease first before removing wheat/gluten from the diet. Mimicking conditions include bowel cancer, endometriosis and ovarian cancer.
What Causes Irritable Bowel Syndrome?
The cause is unknown. Symptoms often (but not always) follow an acute gut infection. One theory is that symptoms are experienced because the bowel is more sensitive than usual, and because muscle contraction within the bowel is poorly coordinated. There is no good evidence that infection with Candida albicans (the "yeast connection") causes irritable bowel, nor that treatment with anti-yeast agents is helpful. While dietary factors can sometimes worsen gut symptoms, irritable bowel is not due to a food allergy and food allergy testing is seldom of use in diagnosis.

How common is it?
Symptoms of irritable bowel are quite common (perhaps up to 20% of the population), especially in those who are stressed and have anxiety or depression. Indeed, treatment of these conditions sometimes relieves symptoms of irritable bowel syndrome as well.

What makes it worse?
The severity of symptoms is frequently influenced by:
Dietary factors (eg. dehydration, too much caffeine, food intolerance)
Stress, anxiety
Menstrual cycle

What Type of Tests are Necessary?
A number of tests may be performed to exclude conditions that can cause similar symptoms. Test may include examination of stool ("poo") samples, some blood tests or looking directly into the stomach (endoscopy) or lower bowel (colonoscopy) using a fibreoptic telescope. When necessary, these tests are normally performed under sedation by a specialist gastroenterologist or surgeon.

Treatment Options
Exclude mimicking conditions. eg. lactose or fructose intolerance (which are gut enzyme deficiencies) or celiac disease, which itself is not uncommon.
Identify potential triggers. A symptom diary is helpful in identifying factors that worsen symptoms such as dietary factors or stress so that steps can be taken to manage these.
Set realistic goals. Dietary change and the use of medications can reduce (but not necessarily abolish) symptoms and improve quality of life.
Relaxation therapy or self-hypnosis is useful when stress plays a role.
Exercise is often helpful
Avoid excessive caffeine. This bowel stimulant often worsens diarrhoea and mucus.
Adopt a healthy approach to diet. Eat a variety of foods, including wholemeal bread, fruit, vegetables and have plenty of water to re-establish a regular bowel pattern.
Avoid some foods. Occasionally, excessive wheat bran actually increases wind and bloating, particularly if introduced too rapidly. In these cases, fibre from fruit, vegetables, rice or barley bran may be better tolerated. Sometimes foods like baked beans, soy beans, cabbage or onion can worsen bloating and wind. This is because carbohydrates in these foods can be fermented into additional gas by bowel bacteria.
Medications can be useful. Medications may sometimes help by acting as stool softeners, as artificial "fibre", reducing muscle spasm or by slowing the rate at which food passes through the gut. Older laxatives containing senna are best used infrequently because they can make the problem worse in the long term. Probiotics (such as lactobacilli supplements) sometimes are used.
Elimination diets sometimes help. Some patients find that milk or wheat worsen their symptoms. Sometimes naturally occurring food "chemicals" such as amines, salicylates and MSG can do so as well. The Fodmaps diet is also sometimes helpful. Since irritable bowel is not caused by allergy, allergy testing is of little use in identifying dietary triggers. The only reliable way to sort out whether diet is playing a role is by placing patients on a temporarily "elimination diet" under the supervision of a skilled dietitian. If the diet helps, this is followed by challenges with dietary factors under controlled conditions. The aim is to identify potential dietary triggers so that they can be avoided.

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Irritable bowel syndrome is an uncomfortable but not dangerous condition affecting the small and large intestine. It is a diagnosis of exclusion. Common aggravants include stress, the menstrual cycle and sometimes diet factors. Allergy testing is not useful for diagnosis this condition. Celiac disease should be excluded as a potential mimicking condition. Those with recent onset symptoms, changes in bowel habit or blood or weight should be investigated for an underlying disorder first before diet manipulation is considered. Always check for celiac disease first before removing wheat/gluten from the diet. Mimicking conditions include bowel cancer, endometriosis and ovarian cancer.