It is important at the outset to remember that each person is unique and that many issues and treatments discussed in this booklet will not apply to everyone who has irritable bowel syndrome. The Canadian Society of Intestinal Research does not intend this booklet to replace the care and advice of a physician.
If you suffer from the following symptoms, you may have IBS:
Abdominal pain
Bloating
Constipation
Diarrhea
What is Irritable Bowel Syndrome (IBS)?
IBS is a chronic, often debilitating, functional (meaning disordered function or movement along the bowel) gastrointestinal disorder with symptoms including abdominal pain, bloating, and altered bowel behaviour such as constipation or diarrhea, or alternating between the two stool consistency extremes. It is the most common gastrointestinal diagnosis worldwide and the most common disorder presented by patients consulting a specialist for gastrointestinal conditions.
Researchers estimate that IBS affects 13-20% of Canadians, although in some countries this figure is as high as 30% of the population. In Canada and most Western nations, IBS occurs significantly more often in women than in men but this ratio shifts elsewhere. For example, in India, a diagnosis of IBS is more common in men than in women. IBS can begin in childhood, adolescence, or adulthood and can resolve unexpectedly for periods throughout an individual's lifespan, recurring at any age.
Although each patient has a unique IBS experience within the range of known symptoms, a significant reduction in quality of life is evident for those who suffer from IBS. Interestingly, only about 10% of people with IBS symptoms seek help from a physician.
Over the years, some called this collection of symptoms mucous colitis, nervous colon, spastic colon, and irritable colon, but these are all misleading names, mostly because IBS is not limited to the colon. Sometimes, IBS is confused with colitis or other inflammatory diseases of the intestinal tract but the differences are clear – in IBS, there is no inflammation evident.
Symptom Criteria for IBS
At least 3 months of symptoms over the past 6 months, including recurrent abdominal pain or discomfort* associated with 2 or more of the following:
Improvement of pain with defecation
Onset of pain associated with a change in frequency of stool
Onset of pain associated with a change in form (appearance of stool)
*Discomfort means an uncomfortable sensation not described as pain.
To understand IBS better, a basic explanation of the gastrointestinal (GI) tract is essential. The upper part of the GI tract includes the mouth, esophagus, stomach, and duodenum. Other vital components are the liver, gallbladder, pancreas, and spleen. The lower part of the digestive tract consists of two main parts, the small bowel/intestine (about 6 metres in length), and the large bowel/intestine or colon (about 1.25 metres). The upper portion of the small bowel is the duodenum and jejunum and the lower is the ileum. The colon follows the small intestine and consists of various segments, starting at the cecum and ending in the rectum and anus. (See diagram.)
Digestion begins in the mouth with food processing that is continued in the stomach; however, it is the small intestine's principal function to absorb dietary nutrients, including proteins, carbohydrates, fats, vitamins, and minerals. Bacteria residing primarily in the colon aid the digestive process, while the colon extracts water. The small and large intestines work together in concert with the liver, gall bladder, and pancreas to break down complex foods and to extract the right amount of each nutrient.
The intestine has a thin inner lining, the mucosa, with a surrounding submucosa, where the blood vessels and lymph channels run. Around this is a thick muscular wall, covered by a thin membrane called the serosa. When food enters the esophagus, ring-like smooth muscle contractions intricately timed with nearby muscle relaxations in a process called peristalsis, propel food along the digestive tract. Long muscles farther along in the digestive tract contract differently, helping to mix food with the enzymes, further processing and propelling meal contents and promoting the passage of waste. Although most individuals are aware of intestinal motility (movement) only through having bowel movements, motility occurs constantly and is particularly prominent after meals. Ordinarily, a meal passes through the digestive tract in 24 to 40 hours but this transit time varies greatly from person to person, often depending on dietary intake composition and quantity.
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 colon cancer.
Although not proven, theories exist as to factors that affect IBS symptoms, including:
dietary issues such as food allergies or sensitivities,
neurological hyper-sensitivity within the GI nerves,
physical and emotional stress,
antibiotic use,
gastrointestinal infection,
bile acid malabsorption,
the amount of physical exercise,
chronic alcohol abuse,
abnormalities in gastrointestinal secretions and/or peristalsis, and
acute enteritis, such as traveller's diarrhea, which may precede persistent altered bowel function despite elimination of the affecting organism.
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.
Typical Experiences
Virtually every human being has experienced, at some point in his or her life, abdominal cramping, bloating, constipation, or diarrhea. However, IBS patients experience these multiple symptoms more frequently and intensely to the extent that they interfere with their day-to-day life. Individuals may have different combinations of symptoms and can fall into different sub-groups of IBS, while others have more random gut symptoms.
Stool Consistency and Bowel Habits
Stool consistency may vary enormously, from total liquid form, to stool so hard and separated that it resembles small pebbles. For some, the predominant symptom is frequent watery bowel movements (diarrhea), known as IBS-D. Others predominantly experience a delay in the bowel transit of the stool resulting in hard, difficult to pass stools (constipation), known as IBS-C. Other IBS patients may alternate between diarrhea and constipation and this combination of symptoms is known as IBS-A. Some people never know what to expect from their digestive tract. Interestingly, the three-way split in the number of people with these types of IBS is fairly even.
In IBS patients, the nerve endings of the bowel could be hypersensitive and the muscles that control the bowel hyperactive, increasing secretions. This could lead to a stringy substance (mucus), covering the stool. Because of over-sensitivity and over-reactivity, the bowel responds quite differently to normal gut stimuli, such as the passage of solids, gas, and fluid through the intestines or to external factors such as stress. These unusual movements may result in difficulty passing stool, or urgent elimination. Up to 20% of people with IBS report fecal soiling. Persons with IBS may also experience a feeling of incomplete evacuation (tenesmus) and immense relief of pain on moving the bowels or passing gas.
Pain and Bloating
Normal, Relaxed Bowel
Bowel With Irregular Contractions
Intestinal pain can result as material in one section of the gut passes slowly while material in another section passes 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 may prevent the normal passage of air, triggering bloating, belching, and flatulence. Bloating can become so severe that clothing feels tighter and abdominal swelling becomes visible to others.
The pain experience varies among individuals with IBS in that it may be ongoing or episodes may be sharp and then resolve rapidly. Pain can occur occasionally or frequently, and it can move from one location in the bowel to another very swiftly. Digestive pain often occurs following a meal and can last for hours.
Other Experiences
People with IBS often experience a diversity of strong emotions related to the condition, including anxiety, depression, loss of self-esteem, and possibly, shame, fear, self-blame, guilt, and anger. Fortunately, psychological management of IBS can reduce symptoms for a number of people with these types of symptoms.
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 with IBS have also reported discomfort during sexual intercourse.
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, nature and onset of symptoms, presence or absence of other symptoms, and looking for 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 problems may delay an IBS diagnosis.
Physical examination: During a physical assessment, the patient usually appears normal, although the bowel may seem spastic and tender.
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 anus (colonoscopy/sigmoidoscopy). The scope is made of a hollow, flexible tube with a tiny light and video camera.
The physician may also order routine blood and stool tests to rule out known organic diseases.
A diagnosis of irritable bowel syndrome usually occurs after these steps, and by considering the nature of the patient's symptoms in relation to the Symptom Criteria for IBS.
Managing IBS
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.
Lifestyle
IBS remains a condition that can seriously compromise an individual's quality of life. Pain and frequent bowel movements may make school, work, and social situations difficult. 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 where the toilets are located. Patients with IBS-C are often in such pain that they find even slight body movements uncomfortable.
Particularly when busy, a person might have very little time to eat properly and might not allow sufficient time for a bowel movement. Some IBS symptoms may improve by allowing sufficient time for a regular eating and bathroom routine.
Stress
The gut has its own independent nervous system, separate from the central nervous system, which regulates the processes of digesting foods and eliminating solid waste. This enteric nervous system communicates with the central nervous system and they affect each other.
IBS is not a psychological disorder caused by stress or anxiety. However, if someone who has IBS also suffers from stress, depression, panic, or anxiety, then bowel symptoms may worsen during periods of emotional upset.
A significant number of females with IBS have a history of some kind of abuse and various research supports the theory that their heightened response and extra sensitivity or vulnerability to their bodily functions exacerbates IBS symptoms. To date, most research in this area has focused on females; however, some evidence indicates that men with a history of abuse are also at increased risk for some negative gastrointestinal health outcomes.
Many IBS patients report high levels of stress. Factors such as poor sleep habits, over-work, and the excessive use of caffeine, alcohol, and tobacco may contribute to excess stress. 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.
Hormones
The GI system is very sensitive to adrenaline - the hormone released when one is excited, fearful, or anxious – and to other hormones as well.
Changes in levels of female hormones affect the GI tract and 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 preponderance of IBS in women over men.
Fibre
An important step in controlling the symptoms of IBS is to increase dietary fibre. Increasing fibre intake has other health benefits aside from possibly improving IBS symptoms. For example, soluble fibres also help to delay the absorption of glucose, which is useful in diabetes control, and help to lower blood cholesterol by binding bile acids.
It is important to note that for some IBS-D patients, studies have shown that 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.
Dietary fibre comes from a group of plant substances that 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 versus soluble).
Gradually increase dietary fibre allowing your body to adjust to the change, and be sure to increase the amount of water you drink as well. Your physician may recommend the addition to your diet of one of the many commercially prepared, concentrated fibre compounds on the market such as Benefibre®, Metamucil®, Fibresure™, or Prodiem®.
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), and hemicellulose (found in cereals and vegetables).
"Friendly" microorganisms in the colon breakdown cellulose and hemicellulose into useable form and may be instrumental in converting toxic or carcinogenic compounds into non-toxic forms.
Soluble fibres form gels when mixed with water, making the bowel contents more viscous so that food stays in the digestive tract longer. This is important for people who suffer from diarrhea. The following is a partial list of foods containing soluble fibre:
pectins (apples, bananas, grapefruit, oranges, strawberries) and
Intestinal Gas
IBS patients do not necessarily produce more gas than the non-IBS population, but their intestines may be extra-sensitive to passage of gas. Reducing ingestion of swallowed air – the major source of intestinal gas – and avoiding gas-producing foods may help.
Swallowed gas: Such things as gum chewing, poor fitting dentures, a chronic post-nasal discharge, chronic pain, and anxiety or tension all cause more air to be swallowed, as does gulping of food, washing food down with liquids, and sipping hot drinks.
Gas generated by digestion: A common source of indigestible carbohydrate is lactose, found in milk. Lactose intolerance affects nearly 70% of adults worldwide in varying degrees. Milk and milk-based cheese products contain more lactose than cream-based and aged cheeses, which contain very little. A 7-14 day lactose avoidance trial often clarifies the role of lactose in your symptoms. If you are lactose intolerant, you could try lactase-containing commercial products, such as Lactaid® and Digesta®, which aid in lactose digestion. As milk contains many vital nutrients, consult your physician or dietitian before making a decision to eliminate milk long-term from the diet, and have a plan in place to ensure adequate nutrient intake.
Another common source of digestion-produced gas is beans, which contain the complex carbohydrates raffinose and stachyose. The human intestine cannot absorb these carbohydrates on its own because humans do not produce the enzymes necessary for their digestion. Fortunately, certain friendly microorganisms – bacteria and yeasts – that live in the colon are capable of breaking down these carbohydrates so the body can absorb their nutrients. By-products of microorganism digestion are hydrogen, methane, and carbon dioxide gases. Some people find the commercial products Beano® or Digesta® to be helpful in reducing the amount of gas produced by the colonic bacteria.
Besides beans and lactose, many other fruits and vegetables are gas producers; however, not everyone reacts the same way to these foods. Rather than completely eliminating gas-producing foods from the diet and missing out on their important nutrient and fibre benefits, try eating them in smaller quantities throughout the day and gradually increase consumption as tolerated.
Certain artificial sweeteners may cause gas, bloating, diarrhea, and abdominal discomfort if taken in large quantities.
Meal Size and Composition
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 patients report that dietary fats trigger symptoms, as can the food additive MSG (monosodium glutamate). Other IBS patients have found low 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 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 to food that works best for you. Be sure to consult a dietitian before eliminating any food group long-term. For more information on food groups and a balanced diet, consult Eating Well With Canada's Food Guide, available from Health Canada.
Probiotics
Probiotics are the "friendly" living microorganisms usually present in the human gut, which are essential for maintaining normal gastrointestinal function. Some research links the pathogenesis of various chronic intestinal disorders to disturbances in the 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 use of antibiotics since these can disrupt the natural floral balance.
Probiotics have a particular appeal in treating IBS. The challenges of probiotic treatment are plentiful. Many products fail to contain the quantity of live bacteria that their labels claim. Additionally, harsh stomach acids kill most probiotics added to foods, such as yogurt, before they reach the colon where they need to be alive to do their job.
Some commercial products do contain sufficient quantities of probiotics, and have special formulations to get them past the acidic stomach environment. One example of this is the yeast, Saccharomyces boulardii (Florastor™).
The true potential benefits and risks of probiotics in GI health have yet to be determined as research in this innovative field is still in its early stage. 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 alternatives to conventional IBS treatments.
Medications
Researchers are continuing to look for new medications to treat IBS symptoms and your physician may prescribe products other than those listed.
Since IBS represents primarily a motility disorder, the use of drugs that help regulate motility is common. 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.
Anti-diarrheal medications focused on preventing cramps and regulating defecation fall within these two groups:
Group 1 are helpful for those with diarrhea because they alter muscle activity of the intestine thereby slowing down transit time. Patients take these medications from time to time, as needed. These include: non-narcotic loperamide (Imodium®); narcotic agents such as diphenoxylate (Lomotil®), codeine, tincture of opium and paregoric; and anti-spasmodic agents that block the transmission of nerve impulses such as hyoscyamine sulfate (Levsin®), dicyclomine (Bentylol®), and hyoscine butylbromide (Buscopan®). However, for those with IBS-A, anti-diarrheal drugs are generally not helpful long-term, and those who have IBS-C should not take them.
Group 2 help both diarrhea and constipation, so check the product labels carefully to be sure the product you buy will help your particular situation. These products include heterogeneous bulk-formers that adjust stool looseness and frequency by binding to (soaking up) water. Commercial fibre products with these benefits come in the form of bran cereals, ispaghula husk, psyllium seed (Metamucil®), calcium polycarbophil (Prodiem®), guar gum (Benefibre™), and inulin (Fibresure™). Remember to go slowly when adding these products to the diet and increase your water intake.
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 relieving pain and improving disordered sleep. Iberogast, a medicine consisting of plant extracts, is indicated to relieve all IBS symptoms. The effectiveness of these agents differs between individuals. As a rule, avoid laxatives and over-the-counter painkillers.
Loperamide (Imodium®) is also useful in fecal incontinence as it helps tighten the anal sphincter.
IBS Outlook
With understanding and faithful adherence to an individualized treatment program, over time many patients with IBS 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 consistent.
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, hopefully, improve quality of life.
More Information
For ongoing information about IBS, you may wish to consider joining The Canadian Society of Intestinal Research for just $20 annually. In doing so, you will receive the Society's newsletter, The Inside Tract®, on a bi-monthly basis. Each issue has more information about IBS and other gastrointestinal diseases and disorders.
Click here to join The Canadian Society of Intestinal Research.
Are you taking prescription medication for any of the following stomach problems/symptoms:
Stomach pain or discomfort
Heartburn
Sour taste in mouth/acid regurgitation
Excessive burping/belching
Increased abdominal bloating
Nausea
Early satiety
If you answer yes to any one of the symptoms listed above then take this test to see if your current medication is adequately controlling your stomach symptoms.
The PASS Test
PPI* Acid Symptom Suppression Test
*PPI is short for proton pump inhibitor, a class of medication used to suppress the acid in your stomach. These include Losec®, Nexium®, Pantoloc®, Pariet™, and Prevacid®.
)
Stool consistency may vary enormously, from total liquid form, to stool so hard and separated that it resembles small pebbles. For some, the predominant symptom is frequent watery bowel movements (diarrhea), known as IBS-D. Others predominantly experience a delay in the bowel transit of the stool resulting in hard, difficult to pass stools (constipation), known as IBS-C. Other IBS patients may alternate between diarrhea and constipation and this combination of symptoms is known as IBS-A. Some people never know what to expect from their digestive tract. Interestingly, the three-way split in the number of people with these types of IBS is fairly even.
