Irritable Bowel Syndrome - Ibs

1. Irritable Bowel Syndrome
Hossam GHONEIM, MD

3. What is IBS
• Irritable bowel syndrome (IBS) is a
gastrointestinal syndrome characterized by
chronic abdominal pain and altered bowel
habits in the absence of any organic cause.

4. Epidemiology
• Affects between 3-22% of persons worldwide
• Account for up to 50% of gastroenterology
referrals
• $8 billion dollars/yr. spent related to IBS

5. Epidemiology
• 70% are women
• 50% develop symptoms prior to age 35
• 20% between ages 35 and 50.
• Psychiatric illness frequently accompanies it,
but no clear causal link has been established.

6. Etiology
• Remains unclear
• Biopsychosocial model best describes it
– Altered GI motility
– GI hypersensitivity
– Psychosocial factors

7. Is IBS truly psychological
12% 88%

8. Recently
• Proposal of post-
infectious hypothesis
• Proposed association
with serotonin which
may stimulate intestinal
secretion and peristalsis
in addition to visceral
pain receptors via 5-
HT3 and 5-HT4
pathways
– Target of new therapies

9. Diagnosis
• Wide array of
symptoms
• Chronic abdominal pain
and altered bowel
habits remain the
central characteristic of
IBS.
• There are no
biochemical markers
• Symptom-based criteria

10. Diagnosis
• Consensus Statement of the American
Gastroenterological Association (AGA):
– Diagnosis of IBS should be based upon the
identification of positive symptoms consistent
with the condition and excluding in a cost-
effective manner other conditions with similar
clinical presentation.

12. Diagnosis
• ACG review on diagnosis and treatment of IBS
recommends the following labs:
– CBC
– Chemistry panel
– TSH
– FOBT
• In persistent diarrhea type:
– Celiac testing, Lactose intolerance testing, Gluten
free diet trial

13. Diagnosis
• Symptomatically, IBS has been divided into 3
subcategories.
– Constipation Predominant … IBS-C
– Diarrhea Predominant … IBS-D
– Pain Predominant (Alternate) … IBS-A

15. Diagnosis
• The Rome Criteria
– Provides a framework for identifying these
conditions.
– Originally created in 1992 and later revised in
1999 and 2006.

16. Rome Criteria
• 12 or more weeks out
of the last 12 months
with abdominal pain or
discomfort
• Can be continuous or
recurrent
• PLUS >>>
• At least 2 of the
following:
– Pain relieved by
defecation
– Associated with change
in stool frequency
– Associated with a
change in stool
form/appearance

18. Diagnosis
Red Flags .. strongly consider further testing
– Anemia
– FMH of CRC or IBD
– Fever
– Bloody stool
– Nocturnal symptoms
– Large volume diarrhea
– greasy stools
– Onset age >50
– Palpable rectal mass
– Persistent severe
diarrhea or constipation
– Recent Antibiotic use
– Rectal bleeding
– Weight Loss

19. Differential Diagnosis
• IBD- CD, UC
• Medications- Laxatives, Constipating agents
• Infection- Parasitic, Bacterial, Viral, Opportunistic
• Malabsorption- Celiac, Pancreatic Insuff, Lactose
intolerance, NON-coeliac gluten sensitivity
• Endocrine- Hypo/Hyperthyroidism, Diabetes, Addison’s
disease
• Malignancy

20. Lymphoma Crohn’s Disease
VCE

22. Therapeutic Approach
• Establish an empathetic physician-patient
relationship

23. Therapeutic Approach
• Identify associated factors and treat
– Anxiety
– Stress
– Social Phobias
– Depression/Dysthymia
– Panic Disorder
– Substance Abuse
– Previous sexual or physical abuse

24. Therapeutic Approach
Dietary Recommendations
– No specific advice has been shown to be efficacious
in trials
– Expert opinion recommends limiting:
• Alcohol
• Caffeine
• Fat
• Gas producing food
• Exacerbating items known to the patient, ? food allergy
• FODMAP

26. Therapeutic Approach
• Diarrhea-Predominant
– Loperamide 2-4mg up to QID
• Can be used prophylactically with anticipated stress
– Cholestyramine 4g 1-6x/day
• Second line, Level C evidence
– Alosetron
• Restricted use in US, Only women, central and peripheral
5-HT3 receptor antagonist

27. Therapeutic Approach
• Constipation-Predominant
– Fiber 20-30g/day
• Start slow and titrate up/may worsen bloating
– Osmotic Laxatives
• Magnesium Citrate
• Lactulose
• Polyethelyne Gylcol
– Tegaserod 6mg bid
• Selective partial 5-HT4 receptor antagonist
• FDA approved in women for short term use (6 weeks)
• Diarrhea most common side effect
• Ischemic Colitis has been reported

28. Therapeutic Approach
• Pain-Predominant
– Jailwala and colleagues conducted a review of RCT
on pharmacotherapy in Annals of Internal Medicine
in 2000
• Showed smooth muscle relaxants effective for pain-
predominant, however none of them used in the studies
have been FDA approved.

29. Therapeutic Approach
• Pain-Predominant
– Dicyclomine 10-20mg bid to qid
• PRN usage only
• Antispasmotic
– Amitryptyline 10-25mg qhs
• TCA
• Steinhart and colleagues showed in 1 RCT of 14 pts that
amitriptyline showed global improvement in pts. with IBS
• Anticholinergic Side Effects limiting
– Tegaserod

30. Therapeutic Approach
• Antibiotics, There is a growing body of
evidence supporting the role of antibiotics
– Rifaximin
– Ciprofloxacin
– Metronidazole

31. Therapeutic Approach
• Probiotics
– Probiotics are not routinely recommended in
patients with IBS.
– Although they have been associated with an
improvement in symptoms, the magnitude of
benefit and the most effective species and strain
are uncertain

32. Take Home message
• Use a symptom based approach and reasonable lab
approach to diagnose IBS
• Identify red flags
• Tailor your ttt to the patients’ predominant symptom
• Treat coexisting factors depression & anxiety
• IBS-C osmotic laxatives are preferred
• IBS-D Alosetron
• IBS-A TCA
• FODMAP is worth a trial
• Antibiotic and probiotic increasing role in the future

33. Thank You