Irritable Bowel Syndrome

IBS: treatment with dietary modification (4)

1. Lactose-free diet x2 wk 2. Trial of avoiding gas-forming foods: beans, onions, celery, carrots, raisins, bananas, apricots, brussels, broccoli, cauliflower 3. Trial of avoiding caffeine/coffee 4. Trial of avoiding gluten Never all together!

IBS: underlying mechanisms (9)

1. Visceral hypersensitivity 2. Brain-gut interactions 3. Dietary factors 4. Gut microbiome 5. SIBO (small intestine bacterial overgrowth) 6. Inflammation of intestinal mucosa 7. Psychosocial factors 8. Abnormal colonic transport 9. Genetics

IBS-D: medical treatment with Alosteron

5-hydroxytryptamine-3 receptor antagonist For WOMEN Pain AND diarrhea 1/1000: severe constipation or ischemic colitis --> deaths have been reported GI doctors register to prescribe, patient signs consent, monitor closeley

IBS-C: testing

Abdominal X-ray TSH: hypothyroidism Review meds: narcotics Colonoscopy/sigmoidoscopy: >50 or suspect structural lesion

IBS: diagnosis based on Rome III

Abdominal discomfort/pain at least 3 days per month x3 months +2 of the following: 1. Improved with defecation 2. Change in frequency of stool 3. Change in appearance/form of stool

IBS: clinical presentation

Abdominal pain, altered bowel habits without an identified cause

IBS: brain-gut axis and abnormal visceral sensation

Afferent input from gut --> spinal cord, midbrain, limbic system and cortex IBS may be an abnormality of visceral afferent processing

IBS: diagnosis by symptoms using Rome III requires appropriate group of patients

Age <45 No alarm symptoms

IBS: gut microbiome

Altered gut bacteria play role in IBS Increased firmicutes bacteria Increased firmicutes/bacteroides ratio Low bifidobacteria Some abx/probiotics help

IBS-D: ddx Celiac Disease

Autoimmune reaction to gluten (wheat, rye, barley) Blunting of small intestine villi (causing malabsorption and diarrhea) --> lymphocyte infiltration --> inflammation of small intestine

Celiac Disease diagnosis

Biopsy of small intestine Tissue transglutaminase, anti-endomysial antibody, serum IgA: Celiac antibodies

Symptoms in IBD that are usually NOT in IBS

Bleeding Nocturnal symptoms Fever Weight loss Extraintestinal manifestations: skin rashes, eye problems, arthralgia/arthritis Elevated ESR, CRP Mucosa abnormal on colonoscopy: ulcerations, erythema, erosions, granularity

IBS: dietary modification and fiber

Can be helpful for constipation (sometimes IBS-D) Provides stool bulk: pulls water into stool May increase bloating

IBS: carbohydrates

Carbohydrate malabsorption can cause IBS-type symptoms Bloating, diarrhea Offenders: lactose, fructose, sorbitol

IBS: psychological treatments

Cognitive behavioral therapy: teaches a different way of processing GI sx, reduces fear of sx, improves QOL Many patients with IBS DON'T have serious psych problems

IBS: pain description

Crampy Comes and goes May worsen with eating/stress May be relieved with BM

IBS: post-infectious

Develops after episode of infectious enteritis Bacterial (campylobacter, shigella, salmonella), viral (noro), protozoan (giardia) Infectious diarrhea --> develop IBS 6x more

Celiac Disease symptoms

Diarrhea Bloating Weight loss/growth problems: children Loss of bone density Vitamin deficiencies Dermatitis herpetiformis

IBS: psychosocial factors

Do NOT cause IBS Affect how people react to their symptoms Higher prevalence among IBS patients who seek medical care Anxiety, depression, sleep disturbances common

IBS: severe and refractory

Dramatic description of symptoms with urgency and persistence Pt. may request additional tests Avoid repeated diagnostic studies/surgery Set realistic goals Focus on managing symptoms and improving function Best managed by gastroenterologist + PCP

IBS: treatment steps

Educate and reassure- negative tests expected Explain IBS in terms the pt understands Continuity of care + follow-ups Assess for other conditions/psychosocial issues Do not repeat tests for exacerbations of same sx!

IBS: lifestyle changes

Exercise Regular sleep

IBS: FODMAP diet treatment

FODMAPs cause luminal distention, rapid fermentation --> low FODMAP diet can help Limit: fructose, lactose, polyols, fructans, galacto-oligos Ex: eggs, high fructose corn syrup, dairy, beans, soy, grains, wheat bread, sweeteners, apples, apricots *Save this diet modification for last

IBS: FODMAPS

Fermentable oligosaccharides, disaccharides, monosaccharides and polyols Poorly digested/absorbed in small intestine Can alter colonic motility/secretion Low FODMAP diet=beneficial

Alarm symptoms that indicate problems other than IBS (8)

Fever GI bleeding Weight loss Nocturnal symptoms F/h: colorectal cancer, IBD, Celiac disease Age >50 at symptom onset Abnormal physical findings Abnormal labs: anemia, elevated ESR/CRP, electrolyte disturbances

IBS-D: altered bowel habits

Frequent loose stools Small/moderate volume Daytime After eating/morning Preceded by cramp abdominal pain Sensation of incomplete evacuation

IBS-C: ddx bloating

GERD Diet issues: carbonated beverages, lactose, rapid eating Medications: celexicob (arthritis)

IBS: medical treatment of pain with antispasmodics

GI smooth muscle relaxants: hyoscyamine, dicyclomine GI smooth muscle relaxes, reduce colonic motor activity, decrease cramping, helps reduce post-prandial diarrhea (after meals) Peppermint oil (enteric coated): smooth muscle relaxer

IBS: medical treatment of pain with antidepressants

GI tract produces large amount of serotonin Tricyclic antidepressants improve IBS symptoms SSRIs have mixed reviews Can slow intestinal transit time Low doses

IBS-C: medical treatment with Linaclotide

Guanylate cyclase agonist Constipation AND pain Used for patients with persistent constipation despite other treatments

IBS-C: altered bowel habits

Hard, pellet like stools Sensation of incomplete evacuation

IBS: rectal balloon distention tests

IBS pt: pain at lower volume IBS pt: more intense pain People with IBS had lower threshold of VISCERAL pain (not somatic)

IBS: abnormal colonic transit

IBS-C: 25% have slow transit IBS-D: 15-45% have rapid transit

IBS-D: ddx diarrhea

Infection: giardia, aeromonas, pleisomonas (bacteria) Lactose intolerance Medications: metformin, Mg supplements, PPIs, laxatives Dietary issues: caffeine, fructose

IBS-D: medical treatment with anti-diarrheals

Loperamide (imodium) Diphenoxylate/atropine (lomotil) Bile acid binders: cholestyramine, colestipol --> increase bloating and flatulence

IBS-C: ddx constipation

Low fiber diet Medications: narcotics Slow-transit constipation: no pain Pelvic floor disorders of evacuation: could be d/t giving birth

IBS: small intestine bacterial overgrowth

May lead to dysmotility, bloating, diarrhea Detected with hydrogen and methane breath tests (done every 20 minutes for a few hours) Some abx may help-Rifaximin (alters gut flora)

IBS: treatment challenge

Not a single disease- syndrome caused by different problems

IBS: epidemiology

One of the most common GI conditions (25-50% of GI referrals) 10-15% of US pop has IBS Second most common reason for missing work

IBS-C: medical treatment with laxatives

Osmotic laxatives: polyethylene glycol (miralax) Lactulose: cause bloating Milk of magnesia: OTC Do NOT help with pain

IBS: other symptoms

Passage of mucus Bloating Flatulence

IBS-C: medical treatment with Lubiprostone

Prostaglandin derivative Activates chloride channels --> increases fluid secretion into intestine --> softer/more frequent stools SE: nausea Expensive

IBS-C: medical treatment of pain AND constipation with antibiotics

Rifaximin- use for 2 weeks, improves pain and bloating Expensive

IBS: inflammation

Some patients have increased intestinal mucosa inflammation (lymphocytes, mast cells, cytokines) Altered intestinal permeability May be genetic predisposition to IBS Can be part of post-infectious IBS

IBS-C: treatment with probiotics

Some probiotics (bifidobacteria) help with constipation and bloating

IBS-D: testing

Stool cultures O&P Serum tissue transglutaminase IgA, serum IgA: celiac screening Colonoscopy with biopsy: chronic diarrhea evaluation for microscopic colitis 24-hour stool study

IBS: medication therapy goal

Symptom control (no treatment) Give meds for main symptom: constipation, diarrhea, pain or bloating etc.

IBS: gluten intolerance

Symptoms increased with gluten NOT Celiac disease Non-Celiac glutten sensitivity

IBS-D: ddx IBD

Ulcerative colitis: colon; from rectum proximally Chron's disease: colon/small bowel/both; skip areas

IBS: post-infectious risk factors

Young people Depression Anxiety Prolonged fever Longer duration of infection

IBS: more common in...

Young women