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40 Cards in this Set
- Front
- Back
Iritable Bowel Syndrome- why it is important
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IBS is one of the most frequently diagnosed gastrointestinal disorders in primary care and gastroenterology offices
Negative impact on patients quality of life Increasing direct and indirect costs associated with this illness |
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27 year old secretary presents for routine screening.
Symptoms of abdominal pain, bloating and diarrhea, worsened by large high fat meals, stress, menses Symptoms are relieved with defecation Symptoms are 2-3x per month, no interference with daily activity. |
Mild IBS
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34 year old truck driver reports abdominal discomfort, urgency, diarrhea and sometimes fecal soiling worsened by large meals and fatty foods
Symptoms occur 2-3 times per week Associated with loss of work (need for frequent stops to fully evacuate) Psychological distress and impairment |
Moderate IBS
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45 year old women with a long term history of crampy lower abdominal pain, loose stools, incomplete relief of pain after the bowel movement
Unable to work, financial difficulties History of abuse, denies role in illness Frequent physician visits; multiple operations |
Severe IBS
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Epidemiology of IBS
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5-10% of the population are affected
3:1 F:M most have mild IBS IBS- usu under 50 y/o most are 15-34 |
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How does IBS affect quality of life?
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Physical functioning, bodily pain, general health, mental health, emotions, social functioning, vitality
Several studies report that IBS increases the rate of absenteeism Impairs patients functioning when they continue work with symptoms One survey showed that patients missed a mean of 13.4 days from work or school compared with 4.9 of non-IBS patients |
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IBS- definition
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A group of symptoms:
-abdominal pain -constipation and or diarrhea -bloating/distension A "functional" bowel disorder |
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Dx of IBS
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Rome III Criteria
Abdominal pain 3 days/month in the last 12 weeks that is continuous or recurrent Associated with >2 of the following: Improvement with defecation, change in stool frequency, change in stool form Onset >6 months prior to diagnosis |
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Supportive Sx of IBS
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Abnormal stool frequency (<3bm/week; > 3bm/day)
Abnormal stool form (lumpy, hard, loose, watery) Straining with defecation Urgency, incomplete evacuation Bloating, passing mucous |
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Bristol Stool Scale
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Type 1 - Separate hard lumps like nuts (difficult to pass)
Type 2 - Sausage shaped but lumpy Type 3 - Like a sausage but with cracks on surface Type 4 - Like a sausage or snake, smooth and soft Type 5 - Soft blobs with clear-cut edges (passed easily) Type 6 - Fluffy pieces with ragged edges, a mushy stool Type 7 - Watery, no solid pieces (entirely liquid) |
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IBS pathophysiology
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Neuromuscular dysfunction
Abnormal colonic motility Visceral Hypersensitivity Abnormal Brain- GI tract interactions Immune activations Genetic Influence Psychological Distress Intestinal Flora Disturbances |
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Increased Pain Sensitivity in IBS
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pain out of proportion to motility changes, discomfort even during normal events (like having a full rectum)
Pain in areas other than bowels. |
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WHAT NEUROTRANSMITTERS CAUSE NEUROGENIC DEFECTS IN IBS?
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Serotonin (5-hydroxytryptamine, 5-HT) as possible mediator:
Released by mucosal enterochromaffin cells with noxious stimulation Activates peristalsis—abnormalities cause increased/decreased transit Activates sensory pathways that mediate pain |
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CNS modulation: Brain-gut axis
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Neuronal control of the GI tract occurs at several different levels
Enteric nervous system, sympathetic & parasympathetic nervous system, higher brain centers Chemical mediators play a role in sensation and GI motility (dopamine, norepinephrine, serotonin, acetylcholine) |
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Immune System Activation Post Inffectious IBS
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1/3 pts say their IBS started after acute enteric infection
10-30% of pts presenting with an acute enteric infection fo on to develop IBS like Sx 6-27% develop PI IBS after e.coli or c. jejuni |
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T cell activation in IBS
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Blood samples from 100 IBS, 44 controls
Colonic biopsies: 11 IBS, 10 controls *(three different cohorts)* Blood and colonic mononuclear cells stimulated with anti CD3/CD28 Antibodies Proliferation Cytokine secretion T-cell phenotype IBS symptom severity was assessed IBS pts have incr IL-1B they also display and activated phenotype |
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Psychological distress and IBS
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Psychological stress exacerbates gastrointestinal symptoms
Psychosocial disturbance affects illness experience and behavior (sexual and physical abuse) IBS can lead impaired health related quality of life. |
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Evidence of heredity in IBS
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incr freq with first degree relatives, monozygotic twins
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Small Bowel Bacterial Overgrowth
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Abdominal pain, bloating are also found in SBBO
Of 202 IBS pts (Rome II), 158(78%) had SBBO. 47 with follow up testing 25 pts eradication of SBBO &improved abdominal pain, diarrhea. (p<0.05) 48% eradicated patients no longer met Rome criteria |
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Evolving model of IBS
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brain-gut. psycho social, visceral hypersensitivity, gut immune interactions, altered motility and secretion
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DX of IBS
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Symptom based criteria are useful for clinical research and clinical practice.
Extensive diagnostic testing is not required unless there are red flag symptoms (weight loss, fevers, blood in stool, anemia, etc.) Red flag symptoms require more extensive evaluation Consider: CBC, ESR, CRP, Metabolic profile, stool cx, stool O&P, WBC and c-difficile toxin Celiac antibodies (total serum IgA and tissue transglutaminase antibodies) Flexible sigmoidoscopy or colonoscopy |
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Tx of IBS
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Provide reassurance/education
Treat according to predominant symptom Assess response to therapy in 4-6 weeks. |
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Tx of IBS: mild Sx
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cut out Coffee/caffeine, alcohol, fatty foods, dairy
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Tx of IBS Moderate Sx
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keep track of foods, drinks and stressors, keep track of timing and severity of Sx
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Behavioral Tx
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Relaxation Therapy, hypnosis, biofeedback, cognitive behavioral therapy
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Bulking Agents
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(psyllium, wheat bran, corn fiber) increase stool frequency ease stool passage through acceleration of colonic transit.
Side effects include gas, bloating |
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Laxatives
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Stimulant laxatives: (bisacodyl, senna)-
Stimulate motility Increase intestinal secretion Side effect: cramps |
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Osmotic Laxatives
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increases water retention
Magnesium Salts Sodium phosphate Lactulose Sorbitol Polyethylene Glycol |
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Lubiprostone
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Approved for chronic functional constipation (January 2006); IBS-C
Bicyclic fatty acid metabolite of prostaglandin E1. Increases intestinal fluid secretion by stimulating a specific intestinal chloride channel (ClC2) in apical membrane No change in electrolyte concentrations in the serum |
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Loperamide
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Slows transit time through colon
Increasing resorption of intestinal water |
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Diphenoxylate w/ atropine
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Reduces transit time
Reduces intestinal muscle spasms Anticholinergic activity |
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Tx of IBS: severe Sx
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antidepressants
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Treatment of Pain and bloating
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Antispasmodics (dicyclomine, hyoscyamine) relieve abdominal pain by inhibiting smooth muscle contraction
5HT3 antagonists 5HT4 agonists Anti-depressants: TCA and SSRI's Antibiotics Probiotics |
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Alosetron
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5 HT3 antagonist- targets serotonin receptors in the gut. reduced visceral pain, slowed colonic transit
Originally approved for women with IBS-D Side Effect: constipation; ischemic colitis Recently reintroduced after 12 week multicenter, randomized placebo study Lowest dose most effective (0.5-1.0mg) with less risk of severe constipation Approved only for women with severe IBS-D. |
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Tegaserod Maleate
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now totally off the market
Stimulate intestinal motility via cholinergic transmission (5HT4 agonist) Augment the peristaltic reflex Enhance intestinal secretion Reduce visceral hypersensitivity Short-term treatment of women with IBS-C (2002). Chronic constipation in men and women younger than 65 years (2004). Removed from the U.S. market Increased risk of serious cardiovascular adverse effects |
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Tricyclic Antidepressants and IBS
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IBS
Migraines Fibromyalgia Interstitial cystitis Neuropathic pain Extensively studied Used at low does Diarrheal predominant IBS (Desipramine, amitriptyline,) |
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SSRIs and IBS
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Fewer placebo controlled trials
Improvement of health related quality of life, symptom frequency and abdominal pain Role in treating depressed and non-depressed IBS patients |
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Role of ABX and IBS
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Treatment of patients with bacterial overgrowth (diagnosed often with hydrogen breath testing)
Rifaxamin, Metronidazole, Quinolones |
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probiotics and IBS
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Systemic Review of RCTs
Evaluate the efficacy, safety and tolerability of probiotics in treatment of IBS 16 RCT met criteria (11 studies suboptimal) Limited data on tolerability and adverse events Bifidobacterium infantis 35624 showed improved pain/discomfort, bloating/distention bowel difficulty |
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Comprehensive Approach to Tx
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Education/ Reassurance
Dietary Modification Pharmacotherapy of gut symptoms Psychological therapy Antidepressants (low dose) Referral to pain management |