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Dr. Mohamed AlshekhaniProfessor in Medicine

MBChB-CABM-FRCP-EBGH 2016

Irritable bowel syndrome (IBS):

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

BO5:1

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

BO5:2

• 2. Irritable bowel syndrome is currently diagnosed by:

• Rome 1 criteria.• Rome 2 criteria.• Rome 3 criteria.• All of the above.• None of the above.

BO5:3

• 3. Irritable bowel syndrome is usually diagnosed by:

• Exclusion.• Symptom – based.• Immune markers.• Serum markers.• All of the above.

BO5:4

• 4.The following are subtypes of Irritable bowel syndrome except:

• IBS-C.• IBS-D.• IBS-U.• IBS-S.• IBS-M.

BO5:5

• 5.The following are parts of Rome 3 criteria for diagnosis of IBS except:

• Abdominal pain.• Diarrhea.• Mucus in stool.• Improvement with defecation.• Constipation.

BO5:6

• 6.IBS is diagnosed when the symptoms fulfills Rome 3 criteria in the absence of:

• Depression.• Anxiety.• Red flags.• Family history of the condition.• Headache.

BO5:7

• 7.The only lab test which may be needed for investigating a case of Rome 3 –diagnosed IBS is :

• CBP.• GSE.• GUE.• Celiac serology.• Abdominal utrasound.

BO5:8

• 8.The lab test needed for investigating a case of Rome 3 – diagnosed IBS-D is :

• CBP.• GSE.• GUE.• Celiac serology.• Abdominal utrasound.

BO5:9

• 9.The lab test needed for investigating a case of Rome 3 – diagnosed IBS-M is :

• CBP.• GSE.• GUE.• Celiac serology.• Abdominal utrasound.

BO5:10

• 10.The cornerstone for effective management of Rome 3- diagnosed IBS is :

• Exclusion of psychiatric diseases.• Exclusion of pathological conditions.• Solid diagnosis & reassurance.• Exhaustive investigations.• Drug treatment in all cases.

BO5:11

• 11.Treatments of choice for IBS-C include all except:

• Fiber diet.• PEG laxative.• Lactulose.• Tricyclic antidepressant.• Linaclotide.

BO5:12

• 12.Treatments of choice for IBS-D include all except:

• Loperamide.• Diphenoxylate.• Antispasmotics.• SSRI.• Rifaximine.

BO5:13

• 13.Treatments for severe refractory IBS include all except:

• Pain clinic referral.• Cognitive behavioral therapy.• Surgery.• Hypnotherapy.• Acupuncture.

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.