Irritable Bowel Syndrome

Focus on CME at xxxMemorial University of Newfoundland

How to Know It’s IBS

Ford Bursey, MD, FRCPC, FACP Presented at Wednesday at Noon—Ask the Consultant, Memorial University teleconference

ymptoms compatible with a diagnosis Peter’s pain Sof irritable bowel syndrome (IBS) are common, especially in Western societies.1 Peter, 26, presents with a two- Some population-based epidemiologic stud- year history of abdominal pain ies suggest a high prevalence of symptoms, and irregular bowel movements characterized by fecal urgency, with up to 25% of women and 20% of men occasional tenesmus, and mucus affected. Probably less than one-third of per rectum. The abdominal pain is affected individuals seek medical attention relieved by defecation, though on for these symptoms. Patients with IBS often occasion the pain may actually report a poor quality of life. It is important worsen for a variable period of to be aware of potential factors that may time post-bowel movement. Peter is concerned about a possible contribute to the health-care seeking behav- intestinal infection in light of the iour. Concern about possible serious under- mucus discharge. lying illness or recent social embarrassment relating to fecal urgency may be the precip- Important questions to ask in this scenario: • Are there constitutional symptoms, such as weight loss or itant that lead to the health-care visit. rectal bleeding? The severity of symptoms in IBS typi- • Is there a family history of inflammatory bowel disease or cally varies over time. This condition usual- colorectal neoplasia? ly begins in late teens or early adult life. It is • Why has Peter chosen to seek medical attention at this time? not unusual, however, to have symptoms For a discussion of this case, see page 67. compatible with IBS begin after the abrupt onset of an infectious gastroenteritis. If the patient is presenting for the first time and is over 50, 1) Abdominal pain relieved by defecation, appropriate screening for colon cancer would seem pru- 2) Onset of pain associated with a change in frequency dent, given the frequency of this condition. of stool, or 3) Abdominal pain associated with a change in the How is IBS diagnosed? appearance of the stool.2 The 12 weeks of symptoms need not be continuous, Several groups have suggested a working definition for as symptoms often fluctuate and may resolve complete- this syndrome. The Rome II criteria require a history of ly for periods of time. Some patients may identify trig- at least 12 weeks during the past 12 months of abdomi- gers for recurrence of symptoms. The stool may be hard nal discomfort or pain that is associated with at least two or watery and may alternate in consistency. A sense of of the following three features: abdominal bloating, as well as passage of mucus rectal-

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Discussion of this case of IBS

Symptoms compatible with a diagnosis of IBS are very If a small amount of bright rectal bleeding had been common in the general population, though most people present, one should not assume that it was hemorrhoidal do not seek medical attention, particularly if the symp- in nature without appropriate investigations. This toms are stable over time. essentially means a digital rectal examination and either Abdominal pain that is altered by defecation is a cardinal a proctoscopy or, preferably, a sigmoidoscopy. The manifestation of IBS, though the intensity of the absence of external hemorrhoids does not rule out discomfort may be quite variable. Many patients develop isolated internal hemorrhoids; nor does the presence of an awareness of possible triggers for exacerbation of external hemorrhoids exclude conditions such as symptoms. One should always be cognisant of reasons ulcerative proctitis. Many patients with ulcerative for health-care seeking behaviour. These may include proctitis will describe intermittent symptoms over a such things as life stressors at home or at work, or the prolonged period of time before a diagnosis is made. In discovery of IBD or colon cancer in a family member. fact, it is not unusual for symptoms compatible with This is not meant to be an exhaustive list, just to ulcerative proctitis to resolve completely without any highlight awareness of why health care is being sought. therapeutic intervention.

ly are also seen in patients with IBS and contribute to a criteria are applied. Care must be taken to exclude sig- diagnosis of IBS. Straining at stool, fecal urgency, and a nificant symptoms, such as rectal bleeding, weight loss, sense of incomplete rectal evacuation, while potentially and anemia. These important historical points have col- distressing to patients, are associated symptoms that one lectively been called “red flags.” It is also important to may see in IBS. The more symptoms present, the more inquire about possible food intolerances, such as lactose, likely is the diagnosis of IBS. Patients with IBS describe fructose, and wheat or gluten. It is not unusual for patterns of abnormal stool fre- patients to have the co-existence quency which are approximate- of two common conditions, ly evenly distributed between 25% of women and 20% of such as lactose intolerance and diarrhea predominant, consti- men are affected by IBS IBS. Age of onset of symptoms, pation predominant, alternating symptoms. as well as a family history of constipation and diarrhea, or no inflammatory bowel disease or particular pattern whatsoever. colorectal neoplasia are obvi- Occasionally, my colleagues tell me that they investi- ous, important historical points. The presence of these gate patients with suspected IBS so as to reassure them- “red flags,” or other important points, warrants caution selves, or their patients, that serious disease is not being when making a diagnosis of IBS. A clinical diagnosis of missed. Studies have clearly shown that a positive diag- IBS can be made if the appropriate symptoms are pre- nosis of IBS can be made with confidence, if the above sent, potential confounding features (such as food intolerances) are absent, and a physical examination including a digital rectal examination are normal.3 It is also appropriate to perform a complete blood count and Dr. Bursey is an associate arrange a flexible sigmoidoscopy in most patients. professor of medicine, A positive diagnosis of IBS is durable. Studies have Memorial University of shown that up to 97% of patients diagnosed with IBS Newfoundland, St. John’s, Newfoundland. still have similar symptoms many years later. Up to 75% will have maintained the same symptom complex, but Cont’d on page 70

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some will have switched to a different predominant ever increasing amounts of fibre may lead to more dis- symptom. It is necessary to remind oneself, however, comfort with gaseousness, bloating, and altered bowel that any significant change in symptoms, or the devel- habit. This may occur particularly with excess insoluble opment of an abnormality, such as anemia, warrants re- fibre, such as is found in fruits and vegetables. evaluation. While a diagnosis of IBS can be made with If education, reassurance, dietary advice, and the confidence in most patients, there is nothing that pre- therapeutic relationship fail to provide benefit for the vents the development of inflammatory bowel disease or IBS sufferer, then directed pharmacologic intervention colorectal neoplasia. IBS does not predispose patients to may be considered. This approach works best if the pre- these conditions, however. dominant symptom is identified. Despite the frequency of IBS, most of the research has been centred on spe- How is IBS managed? cialty referral clinics. Pharmacologic intervention studies have usually involved short trial periods of only a few It is worthwhile to take the time necessary to make a months, even though IBS is often a chronic, intermittent diagnosis of IBS. Studies have shown that patients with condition.7 Clearly these results may not be applicable to a positive diagnosis of IBS, which has been clearly com- the general population. It is important to be aware that municated to them, do better there is a significant placebo overall. Communicating requires Any significant change response that may be as high as giving the patient an understand- in symptoms, or the 65% to 70% in some trials. ing of the physiology of IBS, For the diarrhea predomi- information about the natural development of an nant individual, judicious use of history and management oppor- abnormality such as anti-diarrheal agents, such as tunities, and setting realistic anemia, warrants loperamide, can be tried. I expectations with regard to believe these are best used for symptom control.4 A well- re-evaluation. short periods only, such as informed patient can participate around very specific social in the management of IBS. The benefit of this manage- events where immediate access to washroom facilities ment approach can be demonstrated in several different may be difficult. Other products, such as psyllium, ways, including better coping skills, less time off work, may be helpful. and less decline in overall quality of life. Patients with Constipation may be managed with increased fibre depression probably do not have an increased risk of intake. It is important to ensure adequate intake of caf- developing symptoms of IBS. However, studies demon- feine-free liquids and adherence to regular exercise. strate that IBS symptoms may cause a decline in sever- Osmotic, non-irritant laxatives are preferred if required al parameters on quality of life scales similar to the for a short period. effects of depression.5 Abdominal pain may be the most difficult symptom Pharmacologic intervention should not be the prima- to manage. Agents, such as Modulon® (trimebutine)‚ ry method of dealing with these patients and as much as and Dicetel® (pinaverium bromide), available in possible discussion of lifestyle issues, dietary manipula- Canada, have the potential to reduce abdominal pain tion and education should be the mainstay of the thera- though the effect is probably modest. A recent systemat- peutic relationship. Fibre supplementation is often used ic review of randomized control trials has suggested that in the management of patients with IBS. An analysis of smooth muscle relaxants may be beneficial when published trials revealed serious concerns about abdominal pain is the predominant symptom.8 It is not methodology with the result that no firm scientific data unreasonable to switch to trimebutine or pinaverium exist to support this approach.6 In fact, persistence with bromide if either has previously failed. Occasionally, tri-

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cyclic antidepressant agents, such as Elavil® (amitripty- References 1. Thompson WG, Longstreth GF, Drossman DG, et al: Functional bowel line)‚ in a low dose may help. One has always to be disorders and functional abdominal pain. Gut 1999; 45(Suppl. 2):1143-7. aware that its use may aggravate constipation and, there- 2. Paterson WG, Thompson WG, Vanner SG, et al: Recommendations for the management of irritable bowel syndrome in family practice. CMAJ 1999; fore, increase the abdominal pain. Narcotics should be 161(2):154-60. avoided at all cost. This review of randomized control 3. Thompson WG: Irritable bowel syndrome: Prevalence, prognosis and consequences. CMAJ 1986; 134(2):111-3. trials suggested that peppermint oil and some Chinese 4. Drossman DA, Thompson WG: Irritable bowel syndrome: A graduated, multicomponent treatment approach. Ann Intern Med 1992; 116(12 Pt herbal medicines warranted further study in the man- 1):1009-16. agement of IBS.8 5. Whitehead WE, Burnett CK, Cook EW, et al: Impact of the irritable bowel syndrome on quality of life. Dig Dis Sci 1996; 41(11):2248-53. Even though the precise physiologic abnormality in 6. Klein KB: Controlled treatment trials in the irritable bowel syndrome: A IBS is unknown, attention has focused on the role of the critique. Gastroenterology 1988; 95(1):232-41. 7. Jailwala J, Imperiale TF, Kroenke K: Pharmacologic treatment of the 5-hydroxytryptamine (serotonin) neurotransmitter sys- irritable bowel syndrome: A systematic review of randomised, controlled tem. There are several receptor subtypes within the gas- trials. Ann Int Med 2000; 133(2):136-47. 8. Poynard T, Naveau S, Mory B, et al: Meta-analysis of smooth muscle trointestinal tract. Zelnorm™ (tegaserod), which act as a relaxants in the treatment of the irritable bowel syndrome. Aliment partial selective agonist of 5-HT4 receptors, can accel- Pharmacol Ther 1994; 8(5):499-510. 9. Muller-Lissner SA, Fumagalli I, Bardhan K, et al: Tegaserod, a 5-HT4 erate small intestinal and colonic motility and reduce the receptor partial agonist, relieves symptoms in irritable bowel syndrome patients with abdominal pain, bloating and constipation. Aliment sensory response to intestinal distension. Tegaserod has Pharmacol Ther 2002; 15(10):1655-66. been shown to be effective and safe in constipation pre- 10. Kellow J, Lee OY, Chang FY, et al: An Asia-pacific, double blind, placebo 9 controlled, randomised study to evaluate the efficacy, safety, and dominant IBS. It has also been shown to be effective in tolerability of tegaserod in patients with irritable bowel syndrome. Gut IBS patients in the Asia-Pacific region, excluding those 2003; 52(5): 671-6. 10 with diarrhea predominant IBS. In Canada, this drug Suggested Readings is approved for use in the management of constipation 1. Paterson WG, Thompson WG, Vanner SG, et al: Recommendations for the management of irritable bowel and abdominal pain in females with IBS. CME syndrome in family practice. CMAJ 1999; 161(2):154-60. 2. Drossman DA, Thompson WG: Irritable bowel syndrome: A graduated, multicomponent treatment approach. Ann Intern Med 1992; 116(12 Pt 1):1009-16. 3. Lynn RB, Friedman L: Current concepts: Irritable bowel syndrome. N Engl J Med 1993; 329:1940-5.

Take-home Net Readings 1. National Digestive Diseases message Information Clearinghouse: http://digestive.niddk.nih.gov/ • Symptoms compatible with a diagnosis of IBS are ddiseases/pubs/ibs_ez/index.htm common, though many people do not seek medical attention for their symptoms. 2. Irritable Bowel Syndrome Association: www.ibsassociation.org • A positive diagnosis of IBS can be made in most patients with minimal investigations. • A therapeutic relationship is important in the ongoing management of this chronic condition. www.stacommunications.com • The IBS patient should be involved in setting realistic goals, and pharmacologic agents may be For an electronic version of necessary in select instances. this article, visit: The Canadian Journal of CME online.

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