This document provides information on irritable bowel syndrome (IBS), including its definition, diagnostic criteria, subtypes, differential diagnosis, evaluation, and management approaches. Some key points: - IBS is a common functional gastrointestinal disorder characterized by abdominal pain and altered bowel habits. It affects 10-15% of the population. - Diagnosis is based on fulfilling the Rome symptom criteria, with subtyping based on predominant stool pattern. Additional testing is usually not needed in absence of alarm features. - Treatment involves reassurance, dietary modifications, antispasmodics, laxatives/antidiarrheals based on subtype, and tricyclic antidepressants/SSRIs for refractory cases.

1. Dr. Mohamed Alshekhani
Professor in Medicine
MBChB-CABM-FRCP-EBGH 2017
1
Irritable bowel syndrome (IBS):

2. IBS:
• A heterogeneous symptom complex characterized by abdominal
pain &altered bowel habits.
• A chronic condition affects 10- 15% of the general population
• Lacks a single unifying pathophysiology & biomarkers.

3. IBS:Diagnosis
• By fulfillment of symptom-based Rome III criteria
• IBS is further subtyped based on the predominant stool pattern as
IBS -constipation (IBS-C), IBS - diarrhea (IBS-D), or mixed (IBS-M).
• Additional symptoms not part of diagnostic criteria but frequently
reported include:
• <3 bowel movements/ week
• >3 bowel movements/day
• Abnormal stool form
• Straining.
• Rectal urgency
• Sensation of incomplete evacuation.
• Passage of mucus
• Bloating.

6. IBS: Rome 4
• IBS is not a diagnosis of exclusion, but should be based on the Rome
symptom criteria plus a few simple tests.
• The updated Rome IV criteria for IBS released.
• A patient who presents with longstanding gut symptoms (6 months
or more) including abd pain& constipation&/or diarrhea&who has
two or more of the following has IBS until proven otherwise:
• • Abdominal pain relieved (or sometimes worsened) by defecation;
• • Abdominal pain associated with an increased stool frequency or
looser stools
• • Abdominal pain associated with a decreased stool frequency or
harder stools.
• The symptoms typically fluctuate over time.

7. IBS: Differential Diagnosis
• A variety of other functional conditions occur with IBS, as
fibromyalgia, functional heart burn,functional dyspepsia, migraine,
adding to symptoms.
• IBS occurs in all ages & racial/ethnic groups, but >in women (67%
more likely than men) & in younger (25% > ≥50 years).
• Pathological colonic diseases must be sought when there are red
flags or any features of these diseases as infections,
IBD,Cancer,ischemic colitis,etc.

8. Evaluation:
• Accurate diagnosis can be made with fulfillment of the diagnostic
Rome 3 criteria without further testing in the absence of alarm
features (anemia; wt loss& family H/O CRC, IBD, or celiac).
• BPR & nocturnal abd pain are poor predictors of organic disease.
• Routine CBP, serum chemistry, thyroid functions, stool studies for
ova/parasites& abdominal imaging is unnecessary.

9. Evaluation:
• Testing for celiac disease with serum IgA–based tTG should be
considered in patients with IBS-D or IBS-M symptoms.
• Breath testing for lactase deficiency or SIBO can be considered
based on initial treatment response &/or presence of risk factors.
• Colonoscopy should be pursued only in patients who meet criteria
for colon cancer screening based on age, race& family history.
• Random colon biopsies should be obtained at the time of
colonoscopy to screen for microscopic colitis in patients with IBS-D.
• There is no established role for food allergy testing in IBS.

11. Management:
• An essential step is clear diagnosis with explanation& reassurance.
• A strong clinician-patient relationship should be established using a
patient-centered approach focused on effective patient & clinician
communication, using open-ended Qs, actively listening& empathy.
• The growing role of presumed food intolerances (> 50% report
symptom onset following meals), dietary interventions include the
avoidance of trigger foods (caffeine, carbonated beverages, or fatty
foods), increased dietary fiber&various elimination diets to restrict
gluten, lactose, fructose, or FODMAPs (Fermentable
Oligosaccharides, Disaccharides, Monosaccharides& Polyols).
• It is best to involve a dietitian when pursuing elimination diets to
ensure safety & improve efficacy.
• These initial management steps may lead to symptom
improvement in mild symptoms.

13. IBS-C:
• For persistent symptoms, directed pharmacologic therapy should be
pursued based on the predominant stool pattern.
• The soluble fiber supplement psyllium has limited efficacy in IBS.
• Insoluble fiber supplements such as bran appear worsens IBS-C.
• Only the osmotic laxative PEG has been tested in IBS.
• Lubiprostone & linaclotide have demonstrated safety/efficacy in
treating the global symptoms of IBS-C.
• Lubiprostone is FDA approved for women with IBS-C
• Linaclotide is FDA approved for IBS-C in adults
• Both are costy.

15. IBS-D:
• The antispasmodic agents hyoscyamine,Mebeverine,&dicyclomine
are used for the short-term treatment of abdominal pain in IBS-D or
IBS-C, although they can cause constipation.
• The antidiarrheal agent loperamide is safe &is only effective for the
bowel symptoms associated with IBS-D.
• The non-absorbable antimicrobial agent rifaximin can be effective
for global symptoms & bloating associated with IBS-D, by altering
the colonic microbial flora.
• The 5-HT3 antagonist alosetron is available for women with IBS-D
whose symptoms have not responded to conventional therapy; but
can cause severe constipation&ischemic colitis with its use.

18. Other therapies:
• When the previously mentioned therapies are unsuccessful, central-
acting agents such as TADs&SSRIs are effective, primarily for overall
symptoms & abdominal pain.
• TADs is preferred in IBS-D given their constipating side effects.
• SSRIs are preferred in IBS-C.

19. Complementary Therapy
• If pharmacologic therapies are not effective or not desired by the
patient, a variety of complementary interventions considered:
• Prebiotics (nondigestible nutrients intended to encourage desirable
bacterial growth)
• Probiotics
• Herbal medicine
• Cognitive behavioral therapy
• Hypnotherapy
• Acupuncture.

21. BO5:1
• 1. Irritable bowel syndrome is:
• Common.
• Uncommon.
• Not uncommon.
• Rare.
• Very rare.

22. BO5:2
• 2. Irritable bowel syndrome is currently
diagnosed by:
• Rome 1 criteria.
• Rome 2 criteria.
• Rome 3 criteria.
• Rome 4.
• None of the above.

23. BO5:3
• 3. Irritable bowel syndrome is usually
diagnosed by:
• Exclusion.
• Symptom – based.
• Immune markers.
• Serum markers.
• All of the above.

24. BO5:4
• 4.The following are subtypes of Irritable bowel
syndrome except:
• IBS-C.
• IBS-D.
• IBS-U.
• IBS-S.
• IBS-M.

25. BO5:5
• 5.The following are parts of Rome 4 criteria for
diagnosis of IBS except:
• Abdominal pain.
• Diarrhea.
• Mucus in stool.
• Improvement with defecation.
• Constipation.

26. BO5:6
• 6.IBS is diagnosed when the symptoms fulfills
Rome 4 criteria in the absence of:
• Depression.
• Anxiety.
• Red flags.
• Family history of the condition.
• Headache.

27. BO5:7
• 7.The only lab test which may be needed for
investigating a case of Rome 4 –diagnosed IBS
is :
• CBP.
• GSE.
• GUE.
• Celiac serology.
• Abdominal utrasound.

28. BO5:8
• 8.The lab test needed for investigating a case
of Rome 4 – diagnosed IBS-D is :
• CBP.
• GSE.
• GUE.
• Celiac serology.
• Abdominal utrasound.

29. BO5:9
• 9.The lab test needed for investigating a case
of Rome 4 – diagnosed IBS-M is :
• CBP.
• GSE.
• GUE.
• Celiac serology.
• Abdominal utrasound.

30. BO5:10
• 10.The cornerstone for effective management
of Rome 4- diagnosed IBS is :
• Exclusion of psychiatric diseases.
• Exclusion of pathological conditions.
• Solid diagnosis & reassurance.
• Exhaustive investigations.
• Drug treatment in all cases.

31. BO5:11
• 11.Treatments of choice for IBS-C include all
except:
• Fiber diet.
• PEG laxative.
• Lactulose.
• Tricyclic antidepressant.
• Linaclotide.

32. BO5:12
• 12.Treatments of choice for IBS-D include all
except:
• Loperamide.
• Diphenoxylate.
• Antispasmotics.
• SSRI.
• Rifaximine.

33. BO5:13
• 13.Treatments for severe refractory IBS
include all except:
• Pain clinic referral.
• Cognitive behavioral therapy.
• Surgery.
• Hypnotherapy.
• Acupuncture.

34. BO5:14
• 14.Red flags that warrants investigations to
exclude an alternative diagnosis for IBS
include all except:
• Anemia.
• Weight loss.
• Age < 50 years.
• Family history of CRC.
• Family history of IBD.

35. BO5:15
• 15.A 33-year-old female sales manager presents for management
of uninvestigated crampy lower abd pain, diarrhea&bloating
that have been troubling her for 15 years. The pain occurs
frequently after meals often relieved for a few minutes by
defecation; loose stools are common with pain. No family H/O
CRC but there is a family H/O celiac dis in her mother No other
red flags (no wt loss, vomiting, bleeding, or other worrying
symptoms). She is well nourished & weighs 77 kg; physical exam
is normal. What should be done next:
• A: Perform a colonoscopy?
• B: Screen for CD serologically on a normal diet?
• C: Perform an OGD with biopsies?
• D: treat the symptoms empirically & reassess?