Symptoms . Diagnosis . Causes . Management . Outlook . More

Irritable Bowel Syndrome

If you suffer from the following ongoing symptoms, you might have IBS:

Abdominal Pain
Bloating
Constipation
Diarrhea

IBS is a chronic, often debilitating, functional gastrointestinal disorder with symptoms that include abdominal pain, bloating, and altered bowel behaviours. These are constipation and/or diarrhea, or alternating between the two stool consistency extremes. IBS is a functional disorder, in that the function or movement of the bowel is not quite right. There are no medical tests to confirm or rule out a diagnosis and yet it is the most common gastrointestinal condition worldwide and the most common disorder presented by patients consulting a gastrointestinal specialist (gastroenterologist).

IBS affects an estimated 13-20% of Canadians, depending on which criteria researchers use to assess symptoms. The lifetime risk for a Canadian to develop IBS is 30%.

IBS can begin in childhood, adolescence, or adulthood and can resolve unexpectedly for periods throughout an individual’s lifespan, recurring at any age. In Canada and most Western nations, IBS seems to arise significantly more frequently in women than in men, but the reason for this remains unclear.

Although each person can have a unique IBS experience within the range of known symptoms, this condition typically decreases a person’s quality of life. Interestingly, only about 40% of those who have IBS symptoms seek help from a physician.

Over the years, some have called this collection of symptoms by many names, including mucous colitis, nervous colon, spastic colon, and irritable colon, but these are all misleading, mostly because IBS is not limited to the large intestine (colon). Sometimes, IBS is confused with colitis or other inflammatory diseases of the intestinal tract, but the difference is clear – in IBS, inflammation or infection is not evident.

Symptoms

Almost every human being has experienced abdominal cramping, bloating, constipation, or diarrhea at some point in his or her life. However, those who have IBS experience these multiple symptoms more frequently and intensely, to the extent that they interfere with day-to-day living.

A person who has IBS is likely to have a sensitive digestive system with heightened reactivity, so that the bowel responds quite differently to normal gut stimuli, such as the passage of solids, gas, and fluid through the intestines. These unusual movements may result in difficulty passing stool, or sudden, urgent elimination. Up to 20% of those who have IBS report untimely passage of stool. Some individuals with IBS may also experience straining to pass stool along with a feeling of incomplete evacuation (tenesmus) and immense relief of pain/discomfort when gas or stool finally passes. A stringy substance (mucus) may cover the stool.

Individuals may have different combinations of symptoms, with one being predominant, while others have more random and unpredictable digestive symptoms. These altering bowel experiences and their unpredictability can lead to a high degree of anxiety for the IBS patient. Stool consistency may vary enormously, ranging from entirely liquid to so firm and separated that it resembles small pebbles. External factors, such as stress, can affect stool consistency. IBS is often broken down into different sub-groups, which are associated with stool consistency.

• IBS-D is when the digestive system contracts quickly, transiting products of digestion rapidly through the digestive tract, resulting in frequent, watery bowel movements (diarrhea).
• IBS-C is when the digestive system contracts slowly, delaying transit time for products of digestion, resulting in hard, difficult to pass, infrequent stools (constipation).
• IBS-A is when the transit time throughout the digestive tract fluctuates and stools may alternate between diarrhea and constipation. These extreme stool consistencies can sometimes even occur within the same bowel movement.

Intestinal pain can result as material in one section of the gut passes through slowly while material in another section passes through quickly. These actions, occurring simultaneously, can result in alternating between constipation and diarrhea, sometimes within the same bowel movement. In addition, prolonged contractions of the bowel might prevent the normal passage of air, triggering bloating, belching, and flatulence. Bloating could become so severe that clothing feels tighter and abdominal swelling becomes visible to others.

Pain manifests in many ways with IBS. It can be ongoing or episodic, come on sharply and then resolve rapidly, occur occasionally or frequently, and move from one location in the bowel to another very quickly. Digestive pain often occurs following a meal and can last for hours. Those who have IBS tend to have a quicker and more intense reaction to digestive tract pain stimuli than do those who do not have IBS.

Other Experiences

Symptoms occurring outside of the digestive tract, possibly related to IBS, can include sleep disturbances, fibromyalgia, back pain, chronic pelvic pain, interstitial cystitis, temporomandibular joint disorder, post-traumatic stress disorder, and migraine headaches. Female patients who have IBS have also reported discomfort during sexual intercourse (dyspareunia).

Patients who have IBS-D or IBS-A often feel unable to engage in work or social activities away from home unless they are certain that there are easily and quickly accessible bathroom facilities available. Patients with IBS-C are often in such pain that they find even slight body movements uncomfortable. Pain and frequent bowel movements or preoccupation with an inability to eliminate stool may make school, work, and social situations difficult.

Those who suffer with IBS may experience some psychological symptoms. These include a diversity of strong emotions related to the condition that range in intensity, including anxiety, depression, loss of self-esteem, shame, fear, self-blame, guilt, and anger. Fortunately, psychological management of IBS can often help reduce these symptoms.

Diagnosis

As the symptoms of IBS are varied and there are no organic tests to determine specifically whether a patient has IBS, part of the diagnostic process is to rule out other known diseases. Typically, a physician takes the following steps to reach an IBS diagnosis:

Medical History: A physician reviews the patient’s medical history, considering bowel function pattern, the nature and onset of symptoms, the presence or absence of other symptoms, and warning signs that might indicate some other diagnosis. It is important to note what symptoms do not relate to IBS and these include weight loss, blood in the stool, and fever. If the need to defecate wakes you from your sleep, you should report this to your physician as it is not typical of IBS and could have other implications.

Bowel pain and uterine/ovarian pain may be difficult to distinguish from each other, so gynecological conditions might delay or confound an IBS diagnosis in women.

Physical Examination: During a physical evaluation, the bowel may have involuntary jerky muscular contractions (spastic) and seem tender, although the patient’s physical health usually appears normal in other respects.

Investigative Testing: There is no test to establish the presence of IBS, but a physician may request tests to rule out other possible diseases. In performing a scope, physicians view the intestinal tract with an instrument that enters the body via the mouth (endoscopy) or the anus (colonoscopy/ sigmoidoscopy). The scope is made of a hollow, flexible tube with a tiny light and video camera.

The physician may also request routine blood and stool tests to rule out known organic diseases. Some symptoms of celiac disease overlap those of IBS, so a family history of this disease might be reason to test for it.

A physician makes a diagnosis of irritable bowel syndrome after taking these steps, and after considering the nature of the patient’s symptoms in relation to the information detailed in the Thirty-Second IBS Test.

Possible Causes

The cause of IBS has not been determined. It primarily presents as a functional disorder with altered patterns of intestinal muscle contractions. While IBS is chronic and painful, there is no evidence for a relationship between this disorder and an increased risk of more serious bowel conditions such as inflammatory bowel disease or colorectal cancer.

Although not proven, theories exist as to factors that influence IBS symptoms, including:

• Neurological hyper-sensitivity within the gastrointestinal (enteric) nerves
• Physical and/or emotional stress
• Dietary issues such as food allergies or sensitivities, or poor eating patterns
• Antibiotic use
• Gastrointestinal infection
• Bile acid malabsorption
• The amount or pattern of physical exercise
• Chronic alcohol abuse
• Abnormalities in gastrointestinal secretions and/or digestive muscle contractions (peristalsis)
• Acute infection or inflammation of the intestine (enteritis), such as traveller’s diarrhea, which may precede onset of IBS symptoms

The gastrointestinal (GI) system is very sensitive to the hormone released when one is excited, fearful, or anxious (adrenaline) and to other hormones as well. Changes to female hormone levels also affect the GI tract, so IBS symptoms may worsen at specific times throughout the menstrual cycle. Since hormones play a role in the transit time of food through the digestive tract, this might account for the predominance of IBS in women.

It is important to note that since there is no definitive proof of the source of IBS, many promoted potential ‘causes’ and advertised ‘cures’ of this syndrome are simply speculation.

Management

The gastrointestinal tract is an extremely complex system, influenced by many nerves and hormones. It is clear that both the secretions and motility of the intestine are affected by the type of food eaten, the frequency and environment of eating, and by various medications.

The most important aspect of IBS treatment is for patients to understand the nature of their unique symptoms and any potential aggravating or triggering factors. Also helpful is recognizing that it may take time before bowel function returns to a more normal state.

Dietary and Lifestyle Modifications

The bowel responds to how and when a person eats, so it is important to eat regular, well-balanced, moderately sized meals rather than erratic, variable meals. Some IBS symptoms may improve by allowing sufficient time for regular eating and bathroom routines.

Some IBS patients report that dietary fats trigger symptoms, as can the food additive MSG (monosodium glutamate). Other IBS patients have found lower carbohydrate diets helpful. Some patients’ symptoms worsen when consuming large quantities of liquids with meals. Others find that cooking vegetables and fruits lessens their IBS symptoms, compared to when eating them raw.

Particularly if the predominant symptom is diarrhea, an IBS patient should avoid or decrease consumption of gastrointestinal stimulants such as caffeine, nicotine, and alcohol.

By keeping a food intake diary and noting any adverse reactions, you can quickly identify and remove problematic food from your diet and determine an approach that works best for you. Be sure to consult a registered dietitian before eliminating any food group long-term. For more information on food groups and a balanced diet, consult Canada’s Food Guide, available from Health Canada.

IBS patients do not necessarily produce more gas than the non-IBS population, but their intestines may be extrasensitive to the passage of gas. Things that might help include reducing ingestion of swallowed air, which is the major source of intestinal gas, and avoiding large quantities of gas-producing foods.

To decrease swallowed air, avoid gum chewing, gulping of food, washing food down with liquids, and sipping hot drinks. Poor-fitting dentures, a chronic postnasal discharge, chronic pain, anxiety, or tension may also contribute to increased air swallowing.

To reduce gas generated by digestion, patients may benefit from managing their intake of indigestible carbohydrates. One common source of digestion-produced gas is beans, which contain the complex carbohydrates raffinose and stachyose. Some people find the dietary supplements Beano® or Digesta® to be helpful in reducing the amount of gas produced by the colonic bacteria as they digest the carbohydrates. Some individuals with IBS could also be lactose intolerant. Lactose, the sugar found in milk, requires an enzyme called lactase for the body to digest it properly, and if a person does not produce sufficient lactase, then milk products can be a source of indigestible carbohydrate. Consult your physician to determine whether this condition may be contributing to your gas symptoms. Lactase is available as a food supplement for those who are lactose intolerant and still wish to consume milk products.

In addition to beans and lactose, many fruits and other vegetables are gas-producers; however, not everyone reacts in the same way to these foods. Rather than completely eliminating gas-producing foods from the diet and missing out on important nutrient and fibre benefits, try eating them in smaller quantities throughout the day and gradually increase consumption as tolerated. Certain low-calorie sweeteners, particularly alcohol sugars, such as mannitol, xylitol, and sorbitol, may cause gas, bloating, diarrhea, and abdominal discomfort if taken in large quantities. (The suffix ‘itol’ denotes sugar alcohols.) 

Fibre

An important step in controlling the symptoms of IBS is to increase dietary fibre from plants, which the human body cannot digest on its own. The fibre content of foods stays the same with cooking, although this process may change its effect in the gut. When considering fibre, it is important to look at both the fibre content of foods and the type of fibre (insoluble or soluble).

Gradually increase dietary fibre, allowing your body to adjust to the change, making sure to increase the amount of water you drink. This will minimize any adverse effects that may arise from a sudden dietary change. Your physician or dietitian may recommend the addition to your diet of one of the many commercially prepared, concentrated fibre compounds on the market, such as Benefibre®, Fibresure™, or Metamucil®.

Insoluble fibres increase stool bulk, increase colonic muscle tone, and accelerate the transit time of gastrointestinal contents, thus relieving constipation.

Water-insoluble fibres include:

• lignin (found in vegetables)
• cellulose (found in whole grains)
• hemicellulose (found in cereals and vegetables)

Soluble fibres form gels when mixed with water, making the bowel contents more sticky and resistant to flow (viscous) so that food stays in the digestive tract longer. This is important for people who suffer from diarrhea.

Some examples of water-soluble fibres include:

• pectins (e.g., apples, bananas, grapefruit, oranges, strawberries)
• gums (e.g., cabbage, cauliflower, peas, potatoes, oats, barley, lentils, dried peas, beans)

It is important to note that for some IBS-D patients, a diet excessively high in bran fibre may trigger more frequent diarrhea, while other types of fibre could still be helpful. Consult your physician or dietitian if you have any questions regarding fibre in your diet.

Stress

Separate from the central nervous system, the gut has its own independent nervous system (enteric), which regulates the processes of digesting foods and eliminating solid waste. The enteric nervous system communicates with the central nervous system and they affect each other. Many IBS patients report high levels of stress, which may relate to factors such as poor sleep habits, working too hard, and the excessive use of caffeine, alcohol, and/or tobacco. IBS is not a psychological disorder, even though stress, depression, panic, or anxiety, may aggravate bowel symptoms. Proper exercise and rest can help reduce stress and positively influence IBS symptoms.

Psychological treatments may augment medical treatment, including relaxation training, time management, lifestyle changes, and cognitive restructuring. See our page on stress management.

Medications

Researchers are continuing to look for new medications to treat IBS symptoms and your physician may prescribe products other than those listed. See the medication chart at the bottom of the page.

Since IBS presents primarily as a motility disorder, physicians usually prescribe drugs that target this condition. These agents, pinaverium bromide (Dicetel®), and trimebutine maleate (Modulon®), help to restore the normal contraction process of the bowel. They are most effective when taken for a full course of treatment and are not designed for immediate symptom relief or sporadic, intermittent use. Dicetel® is a gastrointestinal selective calcium antagonist, which works by blocking calcium uptake, and helps to synchronize the muscle movement of the bowel. Dicetel® treats all IBS symptoms of abdominal pain, bloating, constipation, and diarrhea in both women and men. Modulon® regulates motility by moderating kappa opiate receptor affinity and slows the movements of the bowel.

The following anti-diarrheal medications work by altering the muscle activity of the intestine, thereby slowing transit time:

• non-narcotic loperamide (Imodium®), which is also useful in fecal incontinence as it helps tighten the anal sphincter
• narcotic agents such as diphenoxylate (Lomotil®), codeine, tincture of opium and paregoric
• anti-spasmodic agents that block the transmission of nerve impulses, such as hyoscyamine sulfate (Levsin®), dicyclomine (Bentylol®), and hyoscine butylbromide (Buscopan®)

Anti-diarrheal drugs are generally not helpful long-term for those with IBS-A, and those who have IBS-C should not take them.

Some products can ease both diarrhea and constipation by bulking up the intestine, helping it to function better by regulating content transit time and stool consistency. Included are various bulk-formers, which adjust stool looseness and frequency by soaking up (binding to) water. Commercial fibre products with these benefits come in the forms of bran cereals, ispaghula husk, psyllium seed (Metamucil®), guar gum (Benefibre™), and inulin (Fibresure™). Remember to go slowly when adding these products to the diet and increase your water intake. Check the labels carefully, or consult a pharmacist to ensure the product you obtain will help your symptoms.

Other medications could offer some symptom reduction by working in different ways. For example, pancreatic enzymes such as Cotazym®, Creon®, Pancrease®, Ultrase®, and Viokase® may also work in a small number of cases to relieve symptoms of IBS by facilitating digestion. Bile salt binders such as cholestyramine (Questran®) help against diarrhea, and are especially useful when transit time in the small intestine is very fast. Anti-depressants and anti-anxiety medications in low doses may help the enteric nervous system to relax as well as relieve pain and improve disordered sleep. Iberogast®, a medicine consisting of plant extracts, may help relieve IBS symptoms. The effectiveness of these agents differs between individuals. As a rule, avoid laxatives and over-the-counter painkillers.

Probiotics

Probiotics are the friendly, living microorganisms (bacteria and yeasts) usually living within the human gut, which are essential for maintaining normal gastrointestinal function. These probiotics are often referred to as gut flora, although this term is not strictly correct as flora pertains to plants, not microorganisms. Some research links the origin and development of various chronic intestinal disorders (pathogenesis) to disturbances in the gut flora itself or to the body’s inability to interact properly with the flora. These results have encouraged scientists to develop new ways of modifying the complex intestinal ecosystem as a means of therapy and prompted the medical community to step-up its efforts to reduce the use of antibiotics, since these products can disrupt the natural gut microorganism balance.

While probiotics have a particular appeal in treating IBS, the treatment challenges are plentiful. Many products fail to contain the quantity of live bacteria claimed on their labels. Additionally, harsh stomach acids kill most probiotics (which food producers/manufacturers add to foods such as yogurt) before they reach the colon, where they need to be alive to do their job. If you want to add probiotics to your diet, it is likely you will not find sufficient quantities in yogurt to improve your digestive health, as some marketers might claim.

Some commercial products actually do contain sufficient quantities of probiotics and they have special formulations to get them past the acidic stomach environment. Emerging science suggests that specific probiotics are effective only for particular medical conditions. We urge consumers to ensure that the probiotic they are purchasing is a proven treatment for their medical condition.

An example of one probiotic specifically addressing the symptoms of IBS is the bacterium Lactobacillus plantarum 299V (TuZen™), which has demonstrated effectiveness in relieving abdominal pain, bloating, constipation, and diarrhea. Another example is the friendly yeast Saccharomyces boulardii lyo (Florastor™), which has demonstrated effectiveness in regulating the number and consistency of stools.

The true potential benefits and risks of probiotics in GI health have yet to be determined, but research in this innovative field is advancing quickly. New research has identified a specific probiotic, Lactobacillus reuteri (BioGaia® Drops), effective in early infancy to reduce episodes of colic. As our understanding of the intricate milieu of microorganisms within the human gut deepens, we may be able to customize probiotic therapies as significant and effective IBS treatments.

Outlook

Over time, with understanding and faithful adherence to an individualized treatment plan, many patients with irritable bowel syndrome can look forward to a significant improvement in their condition. In fact, statistics show that approximately 10% of IBS patients get better each year, although a different 10% will develop the condition, keeping the percentage of people in the population with IBS at any given time fairly constant.

IBS remains a condition that can seriously compromise an individual’s quality of life and, regrettably, not everyone with IBS will become symptom-free. In most cases, treatment will be ongoing and individualized to meet the specific patient needs and improve daily function.

Medication and Treatment Charts

Abdominal Pain

Bloating (Abdominal Gas)

Constipation

Diarrhea