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IRRITABLE BOWEL SYNDROME. Kimberly M. Persley, MD. 1849 – W Cumming 1 “ The bowels are at one time constipated, at another lax, in the same person. How the disease has two such different symptoms I do not profess to explain. . . .”. IBS – History.
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IRRITABLE BOWEL SYNDROME Kimberly M. Persley, MD
1849 – W Cumming1 “The bowels are at one time constipated, at another lax, in the same person.How the disease has two such different symptoms I do not profess to explain. . . .” IBS – History Earliest descriptions of symptoms defining IBS • Other historical terms – mucous colitis – colonic spasm – neurogenic mucous colitis – irritable colon – unstable colon– nervous colon– spastic colon– nervous colitis– spastic colitis • 1962 – Chaudhary & Truelove2 Irritable colon syndrome • 1966 – CJ DeLor3 Irritable bowel syndrome References: 1. Cumming. Lond Med Gazette. 1849;NS9;969-973. 2. Chaudhary and Truelove. Q J Med. July 1962;31:307-322. 3. DeLor. Am J Gastroenterol. May 1967;47:427-434.
IBS – History Historical perspective • Long dismissed as a psychosomatic condition1 – no clear etiology – affects predominantly women (~70%of sufferers are women)2– condition not fatal • Attitudes now changing • Incidence and prevalence not extensively monitored in past References: 1. Maxwell et al.Lancet.December 1997;350:1691-1695. 2. Sandler. Gastroenterology. August 1990;99:409-415.
IBS – Signs and symptoms Hallmark symptoms of IBS • Chronic or recurrent GI symptoms – lower abdominal pain/discomfort – altered bowel function (urgency, altered stool consistency, altered stool frequency, incomplete evacuation) – bloating • Not explained by identifiable structural or biochemical abnormalities Reference: Thompson et al. Gut. 1999;45(suppl 2):1143-1147.
IBS – Overview Key facts about IBS • Up to 20% of the US population report symptoms consistent with IBS1 • The most common GI diagnosis among gastroenterology practices in the US2 • One of the top 10 reasons for PCP visits3 • Affects predominantly females (~70% of sufferers)4 • The most common functional bowel disorder5 References: 1. Camilleri and Choi. Aliment Pharmacol Ther. 1997;11:13-15. 2. Everhart and Renault. Gastroenterology. April 1991;100:998-1005. 3. Physician Drug & Diagnosis Audit (PDDA), April 1999, Scott-Levin. 4. Sandler. Gastroenterology. August 1990;99:409-415. 5. Thompson et al. Gastroenterol Int. 1992;5:75-91.
IBS – Overview Key facts about IBS (cont.) • Can cause great discomfort, sometimes intermittent or continuous, for many decades in a patient’s life1 • Can significantly disrupt daily life2 • Can have negative impact on quality of life2 • Current treatment options3 –dietary modification –fiber supplements –pharmacologic agents –psychotherapy • Success of current treatment options in addressing multiple symptoms of IBS has been limited4 References:1. Hahn et al. Dig Dis Sci. December 1998;43:2715-2718. 2. Hahn et al. Digestion. 1999;60:77-81. 3. Drossman. Aliment Pharmacol Ther. 1999;13(suppl 2):3-14. 4. Klein. Aliment Pharmacol Ther. 1999;13(suppl 2):15-30.
Specialists1 ~25% Consulters1 Primary care1 ~75% Nonconsulters1 ~70% Female2 ~30% Male2 IBS – Epidemiology IBS consultation pattern References:1. Drossman and Thompson. Ann Intern Med. June 1992;116(pt 1):1009-1016. 2. Sandler. Gastroenterology. August 1990;99:409-415.
IBS – Epidemiology IBS vs other important disease states • US prevalence up to 20%1 • US prevalence rates for other common diseases2: – diabetes 3% – asthma 4% – heart disease 8% – hypertension 11% References:1.Camilleri and Choi. Aliment Pharmacol Ther. 1997;11:3-15. 2. Adams and Benson. Vital Health Stat 10. December 1991:83. DHHS publication no (PHS)92-1509.
IBS – Burden of disease Productivity burden Absenteeism from work or school during the last 12 months 14 12 10 8 P=0.0001 Days per year 6 4 2 0 IBS Non-IBS Reference:Drossman et al. Dig Dis Sci. September 1993;38:1569-1580.
Psychosocial Factors Vagal nuclei Sympathetic S2,3,4 Altered Motility Altered Sensation Irritable Bowel Syndrome • Biopsychosocial Disorder • Psychosocial • Motility • Sensory • ? Infectious • Prevalence 10%, Incidence 1-2% per Year • Disturbs QOL, Social Function, Healthcare Utilization
IBS – Pathophysiology IBS: Current thinking on pathophysiology Defects in the enteric nervous system may lead to the hallmark symptoms of IBS. • Visceral hypersensitivity1 –Increased visceral afferent response to normal as well as noxious stimuli –Mediators include 5-HT, bradykinin, tachykinins, CGRP, and neurotropins • Primary motility disorder of GI tract2 –Mediated by 5-HT, acetylcholine, ATP, motilin, nitric oxide, somatostatin, substance P, and VIP References: 1. Bueno et al. Gastroenterology. May 1997;112:1714-1743. 2. Goyal and Hirano. N Engl J Med. April 1996;334:1106-1115.
IBS – Pathophysiology Physiological distribution of 5-HT CNS – 5% GI tract – 95% –enterochromaffin cells –neuronal Reference: Gershon. Aliment Pharmacol Ther. 1999;13(suppl 2):15-30.
IBS – Pathophysiology 5-HTreceptor effects • Mediate reflexes controlling gastrointestinal motility and secretion • Mediate perception of visceral pain Reference: Gershon. Aliment Pharmacol Ther. 1999;13(suppl 2):15-30.
IBS – Physiology Comparison of pain thresholds of IBS patients and controls Pain produced by rectosigmoid balloon distension 60 IBS 40 % Reporting Pain 20 Normal 0 20 60 100 140 180 Rectosigmoid balloon volume (mL) Reference: From Whitehead et al. Dig Dis Sci. June 1980;25:404-413. With permission.
IBS – Physiology Comparison of pain thresholds IBS Normal Colonic Distension Ice Water Immersion Reference: Whitehead et al. Gastroenterology. May 1990;98:1187-1192.
IBS – Diagnosis Make a positive diagnosis1,2 Identify abdominal pain as dominant symptom with altered bowel function Look for “red flags” Perform diagnostic tests/physical exam to rule out organic disease Make/confirm diagnosis Initiate treatment program as part of diagnostic approach Follow up in 3 to 6 weeks References: 1. Paterson et al. Can Med Assoc J. July 1999;161:154-160. 2. American Gastroenterological Association. Gastroenterology. June 1997;112:2120-2137.
IBS ROME II CRITERIA • At Least 12 Weeks, Which Need Not Be Consecutive, in the Preceding 12 Months, of Abdominal Discomfort or Pain That Has Two of Three Features: 1. Relieved with Defecation; and/or 2. Onset Associated with a Change in Frequency of Stool; and/or 3. Onset Associated with a Change in Form (Appearance) of Stool Constipation Diarrhea
IBS – Diagnosis “Red flags” may suggest an alternative or coexisting diagnosis Additional diagnostic screening needed for atypical presentations such as • Anemia • Fever • Persistent diarrhea • Rectal bleeding • Severe constipation • Weight loss • Nocturnal symptoms of pain and abnormal bowel function • Family history of GI cancer, inflammatory bowel disease, or celiac disease • New onset of symptoms in patients 50+ years of age Reference: Paterson et al. Can Med Assoc J. July 1999;161:154-160.
IBS – Diagnosis Diagnostic tests—What? When? Who? If patient has typical features of IBS: • If 50 years of age, order CBC, electrolytes, LFTs, screen stool for occult blood, and consider sigmoidoscopy.1 • If 50 years of age, order CBC, electrolytes, LFTs, and perform a colonoscopy or air-contrast barium enema with sigmoidoscopy.1,2 References: 1. American Gastroenterological Association. Gastroenterology. June 1997;112:2120-2137. 2. Paterson et al. Can Med Assoc J. July 1999;161:154-160.
IBS – Diagnosis Differential diagnosis • Malabsorption1 • Dietary factors1 • Infection1 • Inflammatory bowel disease1 • Psychological disorders1 • Gynecological disorders2 • Miscellaneous1 References: 1. Drossman. Aliment Pharmacol Ther. 1999;13(suppl 2):3-14. 2. Moore et al. Br J Obstet Gynaecol. December 1998;105:1322-1325.
IBS – Diagnosis Current management of IBS • Establish a positive diagnosis1 • Reassure patient that there is no serious organic disease or alarming symptoms1 • Success of current treatment options in addressing multiple symptoms of IBS has been limited2 References: 1. Drossman. Aliment Pharmacol Ther. 1999;13(suppl 2):3-14. 2. Klein. Gastroenterology. July 1988;95:232-241.
IBS – Management Current management components of IBS • Education • Reassurance • Dietary modification • Fiber • Symptomatic treatment • Psychological/behavioral options • Realistic goals Reference: Drossman. Aliment Pharmacol Ther. 1999;13(suppl 2):3-14.
IBS – Management Currently available Rx treatments for IBS • Dicyclomine HCl1 • Hyoscyamine sulfate (± other anticholinergics/sedatives)2 • Belladonna and phenobarbital1 • Clidinium bromide with chlordiazepoxide1 • Tegaserod • Alosetron References: 1.PDR®Generics™. 1998:314, 559-561, 873-875. 2.Physicians’ Desk Reference®.1999:2910-2911.
IBS – Management Antispasmodics/anticholinergics Symptomatic treatment—pain1 • Smooth muscle relaxants via anticholinergic effects and/or direct action on smooth muscle2 References: 1. Drossman. Aliment Pharmacol Ther. 1999;13(suppl 2):3-14. 2.Drug Facts and Comparisons®. 1999:298-298c.
IBS – Management Antidiarrheals Symptomatic treatment—diarrhea • Increase stool firmness • Decrease stool frequency • Examples: loperamide, diphenxylate-atropine Reference:Drug Facts and Comparisons®. 1999:324b.
IBS – Management Laxatives and bulking agents Symptomatic treatment—constipation • Increased dietary fiber or psyllium1 • Osmotic laxatives (MgSO4, lactulose)2 • Stimulant laxatives3 • Some laxatives and bulking agents can exacerbate abdominal pain and bloating3 References:1. American Gastroenterological Association. Gastroenterology. June 1997;112:2120-2132. 2. Camilleri and Choi. Aliment Pharmacol Ther. 1997;11:3-15. 3.Drug Facts and Comparisons®. 1999:316-317a.
IBS – Management Tricyclic antidepressants and SSRIs Symptomatic treatment—pain • Reserved for patients with severe or refractory pain Reference: Drossman and Thompson. Ann Intern Med. 1992;116(pt 1):1009-1016.
Lower abdominal pain Bloating Altered stool form Altered stool passage Urgency Anticholinergics1 X X Tricyclicantidepressants X and SSRIs2 Antidiarrheals1 X X X Bulking agents1 X X X Laxatives3 X X IBS – Management Multiple medications needed to treat multiple symptoms References:1. American Gastroenterological Association. Gastroenterology. June 1997;112:2120-2137. 2. Drossman and Thompson. Ann Intern Med. 1992;116(pt 1):1009-1016. 3.Drug Facts and Comparisons®. 1999:316.
INITIAL MANAGEMENT OF IBS Symptom Features Constipation Diarrhea Pain/Gas/Bloat Review Diet History Re: Fiber Intake Yes Yes Yes Additional Tests H2 Breath Test Celiac panel No Abdominal X-ray (KUB During Pain) Therapeutic Trial Antidiarrheal Increase Fiber (20g), Osmotic Laxative Antispasmodic + Antidepressant Camilleri & Prather. 1992
Tegaserod (Zelnorm)(serotinin 4 receptor agonist) • Approved for constipation predominant IBS • 1 pill given twice daily • Improvement of symptoms in women but not men • Use up to 12 weeks • Mild side effects: diarrhea the most prominent side effect
Non-Traditional Remedies • Chinese Herbal Medicine • 116 pts randomized to CHM did better than pts receiving placebo • Peppermint Oil • Relaxation of GI smooth muscle • Meta-analysis showed significant improvement of IBS symptoms • Acupunture • Probiotics • Antibiotics Benoussan A. JAMA 1998 Pittler M. AJG 1998
Surgical Therapy for IBS • IBS symptoms may be attributed to: • Non-functioning gallbladder disease, chronic appendicitis, uterine fibroids, tortuous colon • IBS symptoms rarely improve after surgery • IBS patients 2 to 3 times more likely to undergo unnecessary surgery
Take Home Points • IBS is a chronic medical condition characterized by abdominal pain, diarrhea or constipation, bloating, passage of mucus and feelings of incomplete evacuation • Precise etiology of IBS is unknown and therefore treatment is focused on relieving symptoms rather that “curing disease”
Take Home Points • Although many IBS patients complain of symptoms after eating, true food allergies are uncommon • Specific therapies are determined by individual patient symptoms • Life-style modifications and possible alternative therapies may relieve symptoms • Surgery has NO Role in treatment of IBS