Iritable Bowel Syndrome

IRITABLE BOWEL SYNDROME

IRITABLE BOWEL SYNDROMEGASTROENTEROLOGY-HEPATOLOGY DIVISIONINTERNAL MEDICINE DEPARTEMENTFK-USU/ADAM MALIK HOSPITAL

Irritable Bowel - What is it?2Irritable Bowel - What is it?"The bowels are at one time constipated, another lax, in the same person. How the disease has two such different symptoms I do not profess to explain. (Cumming, London Med Gaz, 1849.)Other names:Mucous colitisSpastic colitisNervous colonIrritable colon Irritable bowel syndrome has been described in various ways in recent medical history, without a definitive description of an underlying mechanism or pathology. W Cumming in 1849 articulated the confusing and frustrating nature of the syndrome for both the physician and the patient. (1)

(1) Cumming W. Electrogalvinism in a particular affliction of mucous membrane of the bowels. London Med Gaz 1849;59:969-73. 3Irritable Bowel - What is it?Abdominal discomfort that isRelieved with defecationAssociated with altered stool frequencyAssociated with altered stool consistencyThe most common description of irritable bowel syndrome is a change in the appearance or frequency of stools, and abdominal pain that is relieved by defecation. (1)

(1) Holten KB, Wetherington A, Bankston L. Diagnosing the patient with abdominal pain and altered bowel habits: is it irritable bowel syndrome? Am Fam Physician. 2003 May 15;67(10):2157-62. PMID: 12776965. (http://www.aafp.org/afp/20030515/2157.html)

4Possible CausesAltered Bowel MotilityAbnormal timing & pattern of contractions w/ food or stressVisceral HypersensitivityAbnormal excitability of neurons & pathwaysPsychosocial FactorsMay affect perceptions or central signal processingNeurotransmitter ImbalanceIncreased serotonin levels?Infection/InflammationInflammatory cytokines may affect bowel sensitizationWhile multiple possible causes of irritable bowel symptoms have been proposed in the medical literature, no single explanation accounts for all cases of irritable bowel syndrome. In most patients, irritable bowel symptoms are likely due to interaction between several of the factors listed. (1)

(1) Horwitz BJ, Fisher RS. The irritable bowel syndrome. N Engl J Med. 2001 Jun 14;344(24):1846-50. PMID: 11407347 (http://content.nejm.org/cgi/content/full/344/24/1846)

5Possible CausesTo date, no single conceptual model can explain all cases of the syndrome.NEJM 2001; 344:1846-1850

What is a Syndrome?SyndromeA pattern of symptoms indicative of some diseaseDifferent causes for same problem?Different problems with similar manifestations?A syndrome is a pattern of symptoms indicative of some disease. (1) A syndrome may be the result of different causes leading to the same problem, or of different problems with similar manifestations. In either case, a syndrome describes a pattern of symptoms that predictably and recurrently clusters together in patients. Thus, irritable bowel is appropriately called a syndrome because it describes a predictable, even if unexplained, pattern of symptoms that occurs in a similar pattern from patient to patient.

(1) Hyperdictionary.com8IBS Does it exist?Irritable Bowel Syndrome Defined by Factor Analysis. Dig Dis Sci 1995; 40: 2647-55.Six Manning criteria: Frequent stools with abdominal painLooser stools with painRelief of pain with defecationAbdominal distensionPassage of mucusA feeling of incomplete evacuation after defecationValidation study1344 studentsMeasured prevalence of 22 GI Sx in past 6 months

Factor analysis:3 three Manning symptoms clustered together among both sexes and racial groupsMore frequent bowel movements with the onset of painLooser stools with the onset of painRelief of pain with defecation3 Manning symptoms did not cluster with each other or with the first three symptoms.BloatingMucusFeeling of incomplete evacuation

Does irritable bowel syndrome exist? A study published in 1995 found that when 1344 students were surveyed for prevalence of Manning Criteria IBS symptoms, factor analysis showed that 3 of the 6 Manning Criteria predictably clustered together representing a reproducible symptom complex. (1)

(1) Taub E, Cuevas JL, Cook EW 3rd, Crowell M, Whitehead WE. Irritable bowel syndrome defined by factor analysis. Gender and race comparisons. Dig Dis Sci. 1995 Dec;40(12):2647-55. PMID: 85365269EpidemiologyIncidence/prevalencePrevalence 3 - 22% world-wideReason for 20 - 50% of gastroenterology visits$8 billion in medical expenses per year in the USA 26% prevalence among children with recurrent abdominal painPredominant age40% onset before age 3550% onset age 35 - 50Predominant genderFemale > Male (2:1) in the US

Prevalence and incidence data for irritable bowel syndrome. (1)


10Irritable Bowel - DiagnosisDifferential DiagnosisWhat is the differential diagnosis for IBS?12Differential DiagnosisInflammatory bowel disease Crohn's disease or ulcerative colitis Medications Laxatives Constipating medications Infections Parasitic, bacterial, viral, and opportunistic Malabsorption syndromes Celiac disease Pancreatic insufficiency Endocrine disorders Hypothyroidism Hyperthyroidism Diabetes Addison's disease

Endocrine tumors (very uncommon) Gastrinoma Carcinoid Colorectal carcinoma Adenocarcinoma Villous adenoma Intestinal pseudo-obstruction Diabetes Scleroderma Lactose intolerance Psychiatric disorders Depression Anxiety Somatization disorder

Multiple differential diagnoses must be considered in the patient with possible irritable bowel syndrome. (1)


13Diagnostic CriteriaManningIBS diagnosed if 3 of the following are present:Abdominal painPain relief with defecationIncreased stool frequency with painLooser stools with painMucus in stoolsFeeling of incomplete evacuationRome IIIAbdominal pain or discomfort for at least 3 days per month for the past 3 months, with at least two of:Improved with defecationOnset associated with change in stool frequencyOnset associated with change in stool formIrritable Bowel Syndrome can be diagnosed based on the Manning (1) or Rome 3 (2) diagnostic criteria.

(1) Fass R, Longstreth GF, Pimentel M, Fullerton S, Russak SM, Chiou CF, Reyes E, Crane P, Eisen G, McCarberg B, Ofman J. Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome. Arch Intern Med. 2001 Sep 24;161(17):2081-8. Review. PMID: 11570936 (http://archinte.ama-assn.org/cgi/content/full/161/17/2081)

(2) Mayer EA. Clinical practice. Irritable bowel syndrome. N Engl J Med. 2008 Apr 17;358(16):1692-9. PMID: 18420501 (http://content.nejm.org/cgi/content/full/358/16/1692)14Diagnostic Red FlagsFurther evaluation is mandated:Weight lossEvidence of bleeding or anemiaSigns of infectionAge over 50 at the onset of symptomsRed Flag symptoms mandating the need for further diagnostic evaluation. (1)


15Diagnostic Sensitivity and SpecificityManning Criteria:2 of 6 present 84-94% Sensitivity & 55-76% Specificity3 of 6 present63-90% Sensitivity & 70-93% SpecificityRome 1:65% Sensitivity & 100% SpecificityPerformance characteristics of the Manning and Rome 1 criteria for diagnosing irritable bowel syndrome. (1)


16Symptom PatternsConstipation PredominantDiarrhea PredominantAbdominal Pain Predominant

SeverityMildCan be ignored if the patient does not think about itModerate Cannot be ignored but does not affect patient's lifestyleSevere/very severeAffects patient's lifestyleIrritable bowel syndrome can be classified into predominant symptom pattern(s) and the degree to which it impacts the patients life. 17InvestigationsWhat tests are needed for IBS?InvestigationsConstipation predominant IBSCBC, TSH, Electrolytes, SigmoidoscopyDiarrhea predominant IBSCBC, TSH, ESR, Electrolytes, SigmoidoscopyAbdominal pain predominant IBSCBC

Initial investigations for IBS can be guided by the patients predominant symptoms: constipation, diarrhea, or abdominal pain. (1)

(1) Holten KB, Wetherington A, Bankston L. Diagnosing the patient with abdominal pain and altered bowel habits: is it irritable bowel syndrome? Am Fam Physician. 2003 May 15;67(10):2157-62. Review. PMID: 12776965 (http://www.aafp.org/afp/20030515/2157.html)result the tests?Meta-analysis of 6 studiesPrevalence of disease if IBS criteria met:Colitis/inflammatory bowel disease = 0.5% - 1.0%Colorectal cancer = 0% - 0.5%Celiac disease = 4.7%Gastrointestinal infection = 0% - 1.7%Thyroid dysfunction = 6%Lactose malabsorption = 22% - 26%Endoscopy, ultrasound, and barium studies only detected organic disease in 1% of patients.CBC and chemistries were unhelpful.

Am J Gastroenterol 2002; 97:2812-9.

Extensive diagnostic testing to rule out other causes besides IBS is not needed if patients meet diagnostic criteria for IBS. A meta-analysis of 6 studies found patients meeting criteria for IBS, with no red flags, had a very low prevalence of other organic disease. (1) Thus, if patients meet the diagnostic criteria for irritable bowel syndrome and have no red-flag symptoms, further testing is not needed.

(1) Cash BD, Schoenfeld P, Chey WD. The utility of diagnostic tests in irritable bowel syndrome patients: a systematic review. Am J Gastroenterol. 2002 Nov;97(11):2812-9. Review. PMID: 12425553

Red FlagsWarrant a more thorough diagnostic evaluation.Weight lossEvidence of bleeding or anemiaSigns of infectionAge over 50 at the onset of symptoms

Patients with red flags should have a more thorough diagnostic evaluation. (1)

(1) Cash BD, Schoenfeld P, Chey WD. The utility of diagnostic tests in irritable bowel syndrome patients: a systematic review. Am J Gastroenterol. 2002 Nov;97(11):2812-9. Review. PMID: 12425553

When can you stop the tests?Bottom line:There is insufficient evidence to recommend the routine performance of a standardized battery of diagnostic tests in patients who meet symptom-based criteria for IBS.

Am J Gastroenterol 2002; 97:2812-9.EvaluationPositive Manning or Rome 3?Absence of alarm symptoms?Symptom Pattern?Also exploreDietary fiber and food intolerancesFamily history of intestinal disease or malignancyFamily stressAbuse history?Depression or anxietyEffect of symptoms on daily lifeSummary overview of the diagnostic approach to IBS:

History. Determine if the patient's symptoms meet the Manning or Rome 3 criteria: ask about the nature and duration of abdominal complaints, about pain and whether it is relieved with defecation or associated with changes in stool form or frequency, and about feelings of incomplete evacuation. Ask about weight loss, intestinal bleeding or fever. Ask about dietary fiber and food intolerances, and any family history of intestinal disease or malignancy. Ask about job or family stress, any abuse history, depression or anxiety, and the effect of symptoms on daily life.

Physical exam and testing. Evaluate whether the patient appears to be in good health and determine if there is weight loss. Perform an abdominal exam, do a rectal exam, and test for occult intestinal bleeding. Obtain a complete blood count to rule out anemia. Evidence indicates further testing on the initial evaluation is unnecessary for patients under 50 who meet the Manning criteria with no "red flags."

Irritable Bowel - ManagementWhat are important parts of the management of IBS?Irritable Bowel - ManagementStrong physician-patient relationshipEducation, reassuranceDietaryReduce EtOH, caffeine, fat (?????)Explore triggersLife stressesFoodsSymptom-specific medicationsPain predominantDiarrhea predominantConstipation predominantOverview of IBS management:

A strong physician-patient relationship is vital to successful management of IBS. Provide reassurance that IBS does not represent serious disease or increased risk of malignancy. Recommend reduced dietary fat, alcohol, and caffeine, and explore with the patient ways to reduce other dietary triggers that aggravate symptoms. Evidence supports medical therapy for specific symptoms: bulking agents for constipation-predominant IBS (wheat bran, psyllium), loperamide for diarrhea-predominant IBS (starting with 2mg four times daily as needed), and tricyclic antidepressants for pain-predominant IBS (starting with scheduled doses of amitriptyline 25mg at bedtime or desipramine 50mg three times daily). Explore life stresses that trigger symptoms, and consider recommending relaxation or cognitive therapy.

Behavior Therapy for IBSProvide information about IBS and normal GI functioning, discuss the role of stress. Analyze the patient's illness in terms of symptoms, circumstances of first onset, symptom triggers, contributing factors, and consequences.Teach relaxation techniques. Teach patients to identify irrational thoughts regarding their GI problems. Discuss ways people cope with the problems that chronic illness brings to daily life. Discuss ways to manage difficulties the individual may have in social situations caused by GI problems.Cognitive-behavioral therapy has been shown to be beneficial for management of irritable bowel symptoms. This slide lists important elements of behavioral therapy for IBS. (1)

(1) Viera AJ, Hoag S, Shaughnessy J. Management of irritable bowel syndrome. Am Fam Physician. 2002 Nov 15;66(10):1867-74. Review. PMID: 12469960 (http://www.aafp.org/afp/20021115/1867.html)26Pharmacologic Treatment - ReviewsAnn Int Med 133: 136.Improved PainAmitryptilineImproved ConstipationIspaghula (Psyllium)OndansetronImproved DiarrheaIspaghula (Psyllium)AmitryptilineOndansetronJFP 52: 942Good evidence forTegaserod for constipation*Alosetron for women with diarrhea IBS *Fair evidence forTCAs for PainLoperamide for DiarrheaBulk for ConstipationAntispasmodics for Global Symptoms

Two reviews have summarized the evidence for pharmacologic treatments for IBS. (1) (2)

(Note alosetron and tegaserod are now only available under limited circumstances for patients who have failed other treatments).

(1) Jailwala J, Imperiale TF, Kroenke K. Pharmacologic treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials. Ann Intern Med. 2000 Jul 18;133(2):136-47. PMID: 10896640 (http://www.annals.org/cgi/reprint/133/2/136.pdf)

(2) Holten KB. Irritable bowel syndrome: minimize testing, let symptoms guide treatment. J Fam Pract. 2003 Dec;52(12):942-50. PMID: 14653980

27Treatment recommendationsConstipation- predominant IBSGuar gum, fiber, exercise, episodic use of antispasmodics, peppermint oil, and adequate fluid intake. Diarrhea-predominant IBSLoperamide, episodic use of antispasmodic agents, peppermint oil, and dietary manipulation Patients with pain-predominant or severe IBSTCAs and psychotherapy should be considered. Treatment recommendations for irritable bowel syndrome with strength of recommendation rating. (1) Strength-of-recommendation ratings are: A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. (2)

(1) Hadley SK, Gaarder SM. Treatment of irritable bowel syndrome. Am Fam Physician. 2005 Dec 15;72(12):2501-6. PMID: 16370407 (http://www.aafp.org/afp/20051215/2501.html)

(2) http://www.aafp.org/online/en/home/publications/journals/afp/afpsort.html28IBS conclusionPerform a symptom-directed history and examUse lab testing judiciously if indicatedDefer further testing or imaging unless clearly indicatedBegin education on the interaction of emotional factors, coping styles, environmental stressors and physiologic factors in IBSBegin working to establish a strong physician-patient relationshipConsider a trial of dietary adjustmentsConsider pharmacologic interventions based on the patients symptom pattern

Summary of evaluation and management of IBS:

Perform a symptom-directed history and exam to determine if the patient meets diagnostic criteria for IBS and whether any red flags are present.Use lab testing judiciously if indicated obtain a hemoglobin level in all patients to detect possible anemia, and consider testing for celiac sprue with anti-endomysial and anti-gliadin antibody levels in patients with diarrhea-predominant symptoms.Defer further testing or imaging unless clearly indicated by elements of the patients medical, family or social history.Begin education on the interaction of emotional factors, coping styles, environmental stressors and physiologic factors in IBS - this may help the patient understand why there is no single abnormality that can be tested for, diagnosed, and fixed.Begin working to establish a strong physician-patient relationship to provide ongoing support, reassurance, and education.For patients with constipation-predominant IBS, consider recommending bulking agents (e.g. wheat bran or psyllium) or tegaserod. For patients with diarrhea-predominant IBS, consider loperamide. Alosetron can be considered for women who have failed other treatment options, though its use is restricted due to the risk of severe constipation.For patients with pain-predominant IBS, consider tricyclic antidepressants for pain relief.For all patients, consider anti-spasmodic medications such as hyoscyamine or dycyclomine for global symptom relief.Consider a trial of dietary adjustments if the history identifies specific factors that aggravate symptoms. While reductions in alcohol, fat and caffeine have been advocated, there is no minimal evidence to support this advice. Relaxation therapy, hypnotherapy, and cognitive therapy may be beneficial for relieving individual symptoms, but high-quality evidence is lacking.

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Iritable Bowel Syndrome