Irritable bowel syndrome Flashcards
rome IV criteria for IBS
-Recurrent abdominal PAIN -> at least one day per week in the last three months, associated with 2 or more of the following criteria:
-1. Related to defecation
-2. Associated with a change in stool frequency -> >3 bowel movements per day or < 3/wk
-3. Associated with a change in stool form (appearance) -> lumpy or hard; loose or watery
-additional issues- abnormal stool passage (straining (can cause hemorrhoids, fainting), urgency, incomplete evacuation, and bloating
IBS pathogenesis
-Abnormal Motility
-Visceral Hypersensetivity
-Post Enteric Infection
-Altered Gut Flora
-Psychosocial Abnormalities
abnormal motility
-too fast or too slow
-Variety of abnormal myoelectrical and motor abnormalities have been identified in the colon and small intestine
-? Primary motility disorder or secondary to psychological stress
visceral hypersensitivity
-Pts often have a lower visceral pain threshold
-more sensitive
-Abdominal pain at lower volumes of colonic gas or balloon insufflation than controls
-Complain of bloating & distention, but absolute intestinal gas volume is normal
-Some report rectal urgency despite small rectal volumes of stool
enteric infection
-10% of patients develop IBS after an episode of bacterial gastroenteritis
-Women and stressed patients at risk
-post infectious IBS
alteration in gut flora
-distention
-flatus
psychosocial abnormalities
- > 50% - depression, anxiety or somatization
who has IBS
-10-15% of adults in US
-Typical onset: late teens to twenties -> late onset is suspicious
-2/3 are women
-Present for at least 3 months before the diagnosis can be considered -> Intermittent vs continuous
DIAGNOSIS OF EXCLUSION
3 categories of IBS
-constipation predominant - IBS-C
-diarrhea predominant - IBS-D
-alternating constipation and diarrhea- harder to treat
IBS-C
-IBS constipation
-infrequent bowel movements < 3 week
-hard or lumpy stools, straining, incomplete
-pain
IBS-D
-IBS diarrhea
-loose or watery stools, or frequent stools > 3 day
-urgency or fecal incontinence
-pain
alarm symptoms of IBS
-Acute onset
-Nocturnal diarrhea- lactose intolerance exception
-Severe constipation or diarrhea
-Hematochezia, melena - except possible hemorrhoids
-Weight loss or fever
-Family hx of cancer, inflammatory bowel disease, or celiac disease
history, physical and labs
-H&P-thorough to exclude organic ds
-Physical usually NORMAL- Lower abdominal tenderness (mild) or bloating
-Labs-should be NORMAL:
-CBC, chemistry, TSH, celiac panel, albumin
-Stool hemoccult
-Sigmoid vs colonoscopy
-Stool specimens if diarrhea -fecal calprotectin, fecal elastase (pancreatic insuff), giardia, c diff
-Lactose tolerance test
differential dx
-Colonic neoplasia
-Inflammatory bowel disease
-Microscopic colitis
-Hyperthyroidism or hypothyroidism
-Infectious
-Malabsorption (celiac disease, bacterial overgrowth, lactase deficiency)
-Endometriosis
-Depression, panic disorder, or anxiety
treatment of IBS
-Reassurance, education, and support
-Reasons for seeking help now:
-Major life events or recent psychosocial stressors
-Concerns about serious underlying disease
-Quality of life and impairment of daily activities
-Identify goals
-Educate
-Diet Hx and symptom diary***
diet
-FODMAPS- fermentable (gas producing), oligosaccharides (wheat, barley, rye), disaccharides (lactose), monosaccharides (free fructose), and, polyols (additives, medications, but also fruits)
-decrease fatty foods, caffeine, carbonated beverages
-fiber supplements helpful for constipation
-lactose, gluten, fruits and vegs
-2 weeks knock out all these foods -> reintroduce foods
pharmacologic therapy
-reserved for pts that dont respond to dietary changes or have moderate to severe symptoms
-Antispasmotics- cramps
-Antidiarrheals
-Serotonin receptor agonists and antagonists
-Mu-opioid receptor agonist and delta-opioid receptor antagonist
-Nonabsorbable antibiotics
-Probiotics
-Psychotropics
-Psychological Therapies
-Anticonstipation
antispasmodic agents
-For cramps and/or diarrhea
-Anticholinergics: before meals and at bedtime
-Hyoscyamine
-Dicyclomine*** (others dont need to know)
-Diphenoxylate Atropine
-Clindinium Chlordiazepoxide
-Side effects: urinary retention, constipation, tachycardia, dry mouth
antidiarrheal agents
-Loperamide (Imodium)
-Best used “prophylacticly” in specific situations
-May cause constipation (antispasmotics preferred)
-Bile acid sequestrants—In patients with persistent diarrhea despite antidiarrheals
serotonin receptor antagonists
-not your go to drug
-Alosetron (lotronex) is a 5-HT3 antagonist that is FDA-approved for the tx of women with severe IBS-diarrhea
-used when diarrhea is predominant symptom and unresponsive to other conventional therapies
-Alter visceral sensation and inhibits enteric cholinergic motor neurons, resulting in decreased pain and motility
-Side effects:
-Constipation (sometimes severe) in 30% of patients
-Ischemic colitis in 4:1000 pts
Mu-opioid receptor agonist and delta-opioid receptor antagonist
-Eluxadoline (Viberzi)-:
-used in selected patients with severe IBS-D that is refractory to all other agents
-associated with a high incidence of severe acute pancreatitis -> cant give to people with no gallbladder
-controlled substances
-last resort
psychotropic agents
-Psychotropic agents: Pain, bloating, diarrhea
-Tricyclic antidepressants: affects motility, visceral sensitivity, and central pain perception
-Amitriptyline 10mg q hs and increased as needed -> low dose doesnt treat depression
-Improvement within 4 weeks
-SE: arrhythmia, MI, stroke, sleepy, HTN/hypotension
-can cause constipation due to anticholinergic effects- amitriptyline
serotonin reuptake inhibitors
-Sertraline 50–150 mg daily
-Paroxetine 10–20 mg daily
-Fluoxetine 20–40 mg daily
-Anxiolytics should not be used chronically
antibiotics
-Nonabsorbable antibiotics: Gas, bloating, change in bowel habits:
-Empiric treatment or bacterial overgrowth test
-Rifaximin, 550 mg three times daily for 10 days
