Lecture 6 IBS Flashcards
What is IBS
Functional gastrointestinal disorder
Characterized by chronic and or recurrent pain or dscomfort and altered bowel habits
Most common GI disorder seen by primary care physicians
T/F IBS is 2-3 times more common in females than males
True
Potential risk factors of IBS
Genetic predisposition
GI Infection with subsequent inflammation may play role
Mechanical irritation to GIT nerves
Stressful life events
Common comorbidities with IBS
Close associated with psychological affective disorders
Overlap with fibromyalgia
Presence of IBD or Colitis
Presence of celiac disease
Pathophysiology: Brain- Gut axis disorder
Sensorimotor disturbances of small/large bowel
May involve both the peripheral enteric nervous system and the central nervous system
May be related to downregulation of serotonin receptors in the GI tract
Symptoms of IBS
Lower abdominal pain - 2/3 of patients
Bloaiting, abdominal distension, gas
Changes in bowel habits, diarrhea( > 3 stools/day), constipation (< 3 stools/week with straining)
Alarm symptoms (red flags) of IBS
Blood in stools
Moderate to severe abdominal pain
Nocturnal symptoms
Progressively worsening symptoms
First incidence >50 yrs of age
Fever
Unexplained weight loss
Potential triggers in IBS
Physchiologcal factors : Anger stress
Diet: Alcohol, cafffeine,lactose,sorbitol
Hormone fluctuation with menstrual cycle
Diagnosis: ROME IV criteria
Recurrent abdominal pain at least 1 day per week during the previous 3 months associated with 2 or more of the following
- related to defacation
- associated with change in stool frequency
- associated with a change in stool form or appearance
“ abdominal pain or discomfort that occurs in associated with altered bowel habits over a period of at least 3 months
Other investigations that are worthwhile
Through history: bowel movements, abdominal pain, triggers, medication history, family history
CBC/differential
Fecal lactoferrin, CRP
Serologic testing for celiac disease
What are the subtypes of IBS
IBS-D ( 40% of patients) - >25% loose stools, <25 hard stools
IBS-C (35%) - <25% loose stools, >25 hard stools
IBS-M (25%)- >25% loose stools, >25% hard stools
IBS-U ( unclassified) Variable on hard and loose stools
Managment of IBS : non pharmacological
Diet, probiotics, prebiotics, lifestyle interventions, psychological therapies
Managment of IBS : psychological
Cognitive behaviour therapy, hypnosis, biofeedback, relaxation techniques, mediation, mindfulness
Managment of IBS: Lifestyle
Physical activity
Alcohol consumption
Caffeine intake ( non evidence that caffeine worsens IBS
Managment of IBS : Diet
Adequate dietary fibre - whole grains cereals, veggies, fruit
Avoid high FODMAPs food
Avoid eating large meals
Avoid food triggers
Avoid things that increase flatulence
What is FODMAPs diet
Fermentable
Oligo
Di- and
Mono-saccharides
And
Polyols
Managment of IBS: prebiotics and probiotics
Pre: food components remain indigestible, which stimulate either the growth or activity of colonic bacteria
Pro: live attenuated microorganisms that affect the composition and or function of gut microbiota.
Shown benefit in overall symptoms
Managment of IBS-C (fibre supplementation)
Water soluble fibre first line
15-20g/day (up to 30g)
If novice start lower at 4-8g/day
May work alone
Insoluble fibre may Worsen Symptoms
Managment of IBS-C : Osmotic Laxatives
Osmotic laxatives: second line
Options: PEG (first choice) or Lactulose (++gas forming)
For severe constipation or prn use for quick relief
- magnesium citrate or magnesium hydroxide
- glycerin suppositories - for immediate relief
- also : stimulants ( Bisacodyl, senna)
Managment of IBS-C: GC-C agonists
MOA, Indications, Dose, Efficacy, Adverse effects
Guanylate Cyclades C agonists
MOA: Activates guanylate cyclase C receptor
Indications: moderate to severe IBS-C
- consider for patients who have not responsded to other agents for IBS-C
-Contraindications for use in children <6 years old
Dose :
-Linaclotide : 290mcg orally once daily on empty stomach
-Plecanatide: 3mg orally once daily
Efficacy:
Bowel movements frequency improves within first week, abdominal symptoms take longer
Adverse effects:
- Common; diarrhea, abdominal pain/cramping, flatulence, bloating
- rare but serious: dehydration
Managment IBS-C : 5HT4 agonist
MOA
Indication
Dose
Efficacy
Adverse effects
MOA: 5HT4 Agonist , resulting in pro kinetic effect
Indication: consider for severe constipation in women with in IBS-C who have not responded to other agents
Dose: pruclaopride 2mg orally once daily, eGFR <30ml/min or > 65 years old: 1 mg orally once daily
Efficacy: increase motility and transit throughout GIT, Improve QoL
Adverse effects : Common : diarrhea, nausea, GI pain, headache
Rare: But serious, Arrhythmias
Lubiprostone
Derivative of PGE1
- causes activation of the intestinal chloride channel
- Enhances intestinal fluid secretion and increases GI motility
Indication: IBS-C in females
- increases spontaneous bowel movements
- reduces abdominal pain and bloating
Dose: 8mcg twice daily with food
Adverse effects: Diarrhea, bloating, nausea, abdominal pain
Managment of IBS-D: Pharmacological strategies
Dietary Managment : first line
- soluble fibre : acts as a bulking agent to improve symptoms
Antidiarrheals: Second line
- Loperamide - Preferred agent
- diphenoxylate -atropine
Bile acid binding resins: if bile acid malabsorption
Managment IBS-D: Rifaximin
MOA
Indication
Dose
Efficacy
AE
MOA: poorly absorbed broad spectrum antibiotic, which alters the gut microflora
Indication: More effective for IBS-D
Dose: 550mg TID x 14 days
Efficacy : Recent meta-analysis showed improvement in global IBS symptoms and bloating, may also decrease pain
AE: Minimal (N/D)
Managment IBS-D: Eluxadoline
MOA
Indication
Dose
AE
Contraindication
MOA: Mu-opioid receptor agonist - acts locally in gut
Indication: Improves stool consistency/ frequency > abd pain/bloating
Dose: 75-100mg BID taken with food
Adverse effects: Nausea, Constipation, pancreatitis
Contraindication: alcohol misuse, history of pancreatitis, liver, disease, biliary duct obstruction, hx cholecystectomy
Pain in IBS: Antipasmodic agents, anticholinergic, GI specific calcium channel antagonist
Anticholinergic:
Dicyclomine 10-20mg 1-4x/day,limit use, take before meals, works quickly
Hyoscine (Buscopan) 20mg QID, limit use, taken before meals, works quickly
GI specific calcium channel antagonist:
Pinaverium 50-100mg tid. AE: epigastric irritation, fullness, constipation. Take with full glass of water, and food
Antipasmodic opioid agonist:
Trimebutine 200mg tid. AE: dry mouth, drowsiness, dizziness.
Pain in IBS: Antidepressents (tricyclic antidepressants)
MOA
Indication
Dose
Efficacy
AE
Tricyclic antidepreesents ( amitryptline, desipramine, imipramine
MOA: anticholinergic and analgesic effect
Indication: for patients with intractable pain
Dose: lower doses often indicated, start at lower
Efficacy: decrease abdominal pain, diarrhea, stool frequency
AE: constipation, sedation, dry mouth, blurry vision, orthostatic hypotension, urinary retention
Pain in IBS: Antidepressants (SSRI)
MOA
Indication
Dose
Efficacy
AE
MOA: selectively inhibits 5HT reupatake in the presynaptic neurons and has minimal effects on norepinephrine or dopamine
Indication: may be more effective in IBS-C; use in patients with comorbid depression or anxiety
Dose:
Citalopram- 20 mg daily
Paroxetine- 20-40mg daily
Efficacy: increases GI motility, works on brain-gut axis
AE: N/D, insomnia or sedation, dizziness, nervousness, sexual dysfunction
Pain in IBS: NHP
MOA
Indication
Dose
Efficacy
AE
Peppermint
MOA: Antipasmodic effect on smooth muscles
Indication: Mya reduce abdominal pain, distension
and flatulence
Dose:
Oil 0.2-0.4 ml tid before meals
Colpermin: 1-2EC capsules tid before meals
Efficacy : more data with IBS-D, however may be effective for IBS-C
AEL Heatburn, mouth ulcerations
Summary of treatment approach for IBS
Constipation, Diarrhea, Pain
Constipation:
Soluble fibre (IBS-C, IBS-M)
Osomotic laxatives ( IBS-C, IBS-M)
GC-c agonist (IBS-C, IBS-M)
5HT4 agonist ( IBS-C,IBS-M)
Diarrhea: all for (IBS-D, IBS-M)
Soluble fibre
Loperamide
Eluxadoline
Cholestyramine
Rifaximin
Pain:
Antipasmodic ( all 3 types)
SSRI (IBS-C,IBS-M)
GC-c agonists (IBS-C)
TCA antidepressants ( IBS-D, IBS-M)
Eluxadoline (IBS-D)
Rifaximin ( IBS-D
