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43 Cards in this Set
- Front
- Back
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What is IBS?
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A group of symptoms:
Abdominal pain Constipation and/or diarrhea (a.k.a. altered bowel habits) Bloating/distension A "functional" bowel disorder (a problem with the function of the bowels, not their physical structure) |
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IBS
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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What are the supportive symptoms 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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From 1 to 7
1 is difficult to pass 7 is entirely liquid You want to be somewhere in the middle |
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Pathophysiology of IBS
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Several mechanisms may explain symptoms of IBS
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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Diarrhea in IBS
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Stronger, more frequent muscle contractions
Feces move through colon too quickly Not enough time to remove water from stools |
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Constipation in IBS
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Less-frequent muscle contractions, or
Strong contractions that block passage of feces Feces move through colon too slowly More water removed from stools |
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Pain and IBS
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Increased Pain Sensitivity
Pain out of proportion to motility changes Discomfort even during normal events (like having a full rectum) Pain ain 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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Brain Gut Axis: CNS Modulation
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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 Infectious IBS |
1/3 of patients with IBS report symptoms began after acute enteric infection (salmonella, shigella and Campylobacter)
10-30% of pts presenting with an acute enteric infection go on to develop IBS-like symptoms Walkerton Health Study- 6-27% of pts develop PI-IBS after E. coli or C. jejuni |
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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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Heredity in IBS?
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Increased frequency of IBS and dyspepsia in adults with an affected first-degree relative
Monozygotic twins more likely to be concordant for IBS than dizygotic twins. >50% of liability to functional bowel disorders might be subject to genetic control. |
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Small Bowel Bacterial Overgrowth
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symptoms of abdominal pain and bloating
can fit the Rome criteria |
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Diagnosis 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 (if red flag sxs) |
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General Treatment for 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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Treatment of Mild IBS
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Eliminate food and drink and medications that make symptoms worse
- coffee/caffeine - alcohol - fatty foods - dairy products |
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Treatment of Moderate IBS
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Symptom Diary
- Keep track of foods, drinks and stressors - Keep track of timing and severity of symptoms Behavioral treatments - Relaxation therapy - Hypnosis - Biofeedback - Cognitive-behavioral therapy Medications - For abdominal pain - For diarrhea - For constipation |
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Bulking Agents
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psyllium, wheat bran, corn fiber
increase stool frequency and ease stool passage through acceleration of colonic transit Side effects include gas, bloating |
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Stimulant laxatives
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bisacodyl, senna
Stimulate motility Increase intestinal secretion Side effect: cramps |
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Osmotic laxatives
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Increase water retention
Magnesium Salts Sodium phosphate Lactulose Sorbitol Polyethylene Glycol |
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Lubiprostone
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Approved for chronic functional constipation (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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Antidiarrheals
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Loperamide
Diphenoxylate w/ atropine |
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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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Treatment of Severe IBS
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Antidepressant medications can reduce the intensity of pain signals going from gut to brain
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Pain and Bloating Therapy
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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 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. Side Effect: constipation; ischemic colitis |
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Tegaserod Maleate
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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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Role of antidepressants in IBS
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Alter pain perception by modulation of visceral afferents
Treat comorbid psychological conditions Alter GI transit |
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Tricyclic Antidepressants and IBS
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Desipramine, amitriptyline
Extensively studied Used at low doses Diarrheal predominant IBS |
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Tricyclic Antidepressants are used to treat...
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IBS
Migraines Fibromyalgia Interstitial cystitis Neuropathic pain |
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Selective Serotonin Reuptake Inhibitors (SSRI'S)
and IBS |
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 Antibiotics in IBS
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Rifaxamin, Metronidazole, Quinolones
Treatment of patients with bacterial overgrowth (diagnosed often with hydrogen breath testing) - to determine if there is increase H because of fermentation |
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Utility of Probiotics in IBS Treatment
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Bifidobacterium infantis 35624 showed improved pain/discomfort, bloating/distention bowel difficulty
No other probiotic showed improvement of IBS symptoms in an appropriately designed study |
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Approach to Treatment of IBS
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Education/ Reassurance
Dietary Modification Pharmacotherapy of gut symptoms Psychological therapy Antidepressants (low dose) Referral to pain management |
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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. Diagnosis? |
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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IBS
Epidemiology |
In US, 5-10%
3 x more common in women Most patients don't go to the doctor, of those that do: 70% Mild 25% Moderate 5% Severe |
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When do patients present with IBS?
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13.5% 15-34 y/o
13% 35-44 y/o 9.4% 45 y/o + |
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IBS
Quality of Life |
Patients with IBS have poorer quality of life than many of those with other chronic medical conditions
- 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
Health Care Costs |
3.6 million visits annually for IBS
>20 Billion in both direct and indirect expenditures |
