IRRITABLE BOWEL SYNDROME

Joseph Zimmerman MDGastroenterology

Hadassah-Hebrew University Medical Center

Jerusalem, Israel

The Irritable Bowel Syndrome (IBS)

“IBS is defined by abdominal discomfort associated with altered bowel habits not explained by structural or known biochemical abnormality”

ACG Position Statement 2002

IBS: The Rome III Criteria for Diagnosis

Recurrent abdominal pain or discomfort at least 3 days/month in the last 3 months associated with 2 or more of the following:• Improvement with defecation;• Onset is associated with a change in the frequency of stool;• Onset is associated with a change in form (appearance) of stool.

OTHER BOWEL SYMPTOMS IN IBS

• Abnormal stool passage (straining etc.);• Passage of mucus;• Bloating or feeling of abdominal distention.

IBS: Clinical Subtypes

• IBS is sub-classified into three types based on the primary bowel symptom:– constipation: IBS-C– diarrhea: IBS-D– alternation between constipation

and diarrhea: IBS-A

• Patients may shift between the various types.

EPIDEMIOLOGY OF IBS

The Irritable Bowel Syndrome

• Symptoms compatible with IBS are present in 7-15% of the general population.

• Females predominate 2:1.• Most of the people who meet diagnostic

criteria for IBS have never consulted a doctor for bowel symptoms (IBS nonpatients).

IBS: A Multidimensional Disorder

• BIOLOGICAL • PSYCHOLOGICAL• BEHAVIORAL

IBS is a Syndrome of Visceral Hyperalgesia

• Low visceral pain threshold;• Normal compliance of the bowel wall;• Normal threshold for SOMATIC pain (in

most but not all studies);• May we widespread;

Mayer EA, Gebhart GF, Gastroenterology 1994;107:271

CONTROLS IBS

Is It in the Brain?

• Some studies have shown that IBS patients differ from control subjects in the pattern of brain activation as a response to balloon distention in the distal colon.

• The reported findings are inconsistent.

ABNORMAL GAS PROPULSION IN IBS

• Abdominal girth normally swells during the day, peaking in the late evening.• This phenomenon is exaggerated in IBS.• Studies using infusion of gas into the small intestine have shown that IBS patients retain more gas than controls, indicating abnormal gas propulsion.

BLOATING AND DISTENTION IN IBS

• During gas infusion, IBS patients, in contrast to healthy controls, involuntarily suppress their abdominal wall muscle contraction, reflecting an abnormal intestinal somatic reflex response.

IBS: Additional Clinical Features

• Non-Digestive Symptoms; Association with fibromyalgia.• Association with other functional GI disorders;• Relationship to enteric infections;

SOMATIC PAIN

0

15

30

NORMAL I BD I BS

IBS = IBD > Normal; F=7.7; p=0.001.

SC

OR

E

URINARY SYMPTOMS

0

20

40

NORMAL IBD IBS

IBS > IBD = normal; F=8.7; p<0.001.

SC

OR

E

SLEEP DISTURBANCES

0

20

40

NORMAL I BD I BS

IBS = IBD > Normal; F=5.5; p<0.001

SC

OR

E

IBS: Additional Clinical Features

•Non-Digestive Symptoms;•Association with other functional GI disorders;•Relationship to enteric infections;

Lower GI tract

Upper GI tract

Functionalconstipation/diarrhea

IBS

Functional abdominalpain

Non-cardiac chest pain

Heartburn

Functionaldyspepsia (FD)

Gastroesophageal refluxdisease (GERD)

GI disorders of function commonly co-exist

IBS: Additional Clinical Features

•Non-Digestive Symptoms;•Association with other functional GI disorders;•Relationship to enteric infections;

Post Infectious IBS

New onset of IBS symptoms following an episode of

infectious enteritis

Postinfectious IBS (PI-IBS):CLINICAL FEATURES

• Usually diarrhea predominant;• The duration of PI-IBS spans months

and years following the episode of acute infectious enteritis.

Postinfectious IBS (PI-IBS):EPIDEMIOLOGY

• Has been described following dysentery (bacillary or amebic), campylobacter infections and salmonellosis.

• PI-IBS developed in 7-31% of cases.

Postinfectious IBS (PI-IBS):PATHOGENESIS

HOST FACTORS PATHOGEN FACTORS

• Biological• Psychological

Postinfectious IBS (PI-IBS):PATHOGEN FACTORS

• The risk varies with the pathogen. • The risk associated with infections

with shigella or campylobacter jejuni is 10-fold higher than that associated with salmonella.

Postinfectious IBS (PI-IBS):Risk Factors for its Development (1)

FACTOR ODDS RATIO

• Female gender 3.4• Duration of diarrhea

• 0-7 days 1.0• 8-14 days 2.9• 15-21 days 6.5• >22 days 11.4

Postinfectious IBS (PI-IBS):HOST FACTORS

• Psychometric testing of patients admitted for acute gastroenteritis revealed that those who scored higher on anxiety, depression, somatization and neurotic traits during the acute illness were more likely to develop a PI-IBS.

Gwee et al, Lancet 1996;347:150-53

Postinfectious IBS (PI-IBS):MUCOSAL ABNORMALITIES1

• Campylobacter infection may cause mucosal changes that persist for months.

• These include enterochromaffin cell hyperplasia and an increase in mucosal T-lymphocyte counts.

• Both changes tend to be more severe in patients with PI-IBS.

1. Dunlop et al. Gastroenterology 2003;125:1651-59

Prevalence of IBS in community-based

populations

IBS features are highly prevalent in the population. Yet, most people with this “trait” do

not consult a doctor for bowel symptoms.

WHAT MAKES A PERSON WITH THE IBS ”TRAIT” BECOME AN IBS

PATIENT?

• PSYCHOLOGICAL FACTORS;• STRESSFUL LIFE EVENTS;• BEHAVIORAL FACTORS;

The Irritable Bowel Syndrome: Psychological Profile of Patients• No pattern of psychological symptoms

is unique to patients with IBS.• IBS patients tend to score high in

somatization, obsessive-compulsive, depression, anxiety and hostility scales.

• In some studies, the proportion of patients meeting a criterion for a psychiatric diagnosis is 54-100%.

The Irritable Bowel Syndrome: Stressful Life Events (1)

• Acute induction of pain or emotional arousal increases the motility of the distal colon under experimental conditions.

• This response is exaggerated in IBS patients1.

• Exacerbation of symptoms is frequently associated with psychological stress.1. Welgan et al., Gastroenterology 94: 1150, 1988

The Irritable Bowel Syndrome: Sressful Life Events (2)

• Studies of the prevalence of stressful life events in IBS patients have yielded inconsistent results.

• Loss of a parent in childhood is an important factor1.

• A history of physical or sexual abuse, particularly at a young age, is significant.1. Lowman et el. , J Clin Gastroenterol 9:324, 1987

The Irritable Bowel Syndrome: ILLNESS BEHAVIOR

IBS PATIENTS:• Make 2-3 times as many visits to

doctors for non-GI complaints than controls1.

• Are more likely to have surgery.

1. Drossman et el. , Dig Dis Sci 38:1569 , 1993

IBS and Surgery

Of 89,009 HMO members, patients diagnosed with IBS (5.2%) were significantly more likely to undergo the above operations:

• CHOLECYSTECTOMY: A 3-fold higher rate;• APPENDECTOMY: A 2-fold higher rate;• HYSTERECTOMY: A 2-fold higher rate;• BACK SURGERY: A 50%-fold higher rate.

Longstreth GF et al. Gastroenterology 2004:126;1665

IBS: ECONOMIC ASPECTS

• IBS is associated with costs because of: Days lost from work; Excess physician visits; Excess diagnostic testing; Excess use of medications;

• In the USA, the estimated annual cost of IBS is 8 billion dollars.

IBS AND QUALITY OF LIFE

IBS: Quality of life impact assessed by theIBS: Quality of life impact assessed by theShort-Form 36 questionnaireShort-Form 36 questionnaire

National NormNational Norm

IBS subjectsIBS subjects

EmotionalEmotional MentalMental VitalityVitality PhysicalPhysicalFunctioningFunctioning

SocialSocial RoleRolePhysicalPhysical

PainPain GeneralGeneralHealthHealth

SF-36 ScalesSF-36 Scales

3030

4040

5050

6060

7070

8080

9090

Sco

reS

core

Wells Wells et alet al, 1997, 1997

IBS: Differential Diagnosis

• CHO maldigestion (i.e. lactase deficiency)• Inflammatory Bowel Diseases• Celiac disease• Laxative abuse syndrome• Panic disorder• Parasitic infections• Carcinoma of colon• Other conditions

IBS: What is against this diagnosis?

• Onset after the age of 50;• Significant weight loss; • Prominent nocturnal symptoms;• Rectal bleeding, anemia;

IBS: Clinical Workup

• Lab: CBC, ESR, CRP, TSH levels;• Serological tests for celiac disease;• Fecal occult blood;• Stool microscopy (in IBS-D) ; • Sigmoidoscopy;

The Management of

Irritable Bowel Syndrome

(IBS)

IBS Management - General

• Reassurance and explanation of the nature of the problem: IBS is a recognized clinical entity; symptoms can fluctuate; diet or stress may precipitate symptoms.

• Dietary counseling (fiber supplementation with psyllium);

• Symptomatic treatment: antispasmodics (papaverine, mebeverine), anti diarrhea agents etc.

Management of Refractory Patients

• Antidepressants• Psychological Treatments:

• Hypnotherapy• Cognitive Behavioral Therapy (CBT)

HYPNOTHERAPY FOR IBS

HYPNOTHERAPY IN IBS

LONG-TERM RESULTS

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PRE POST Tx 1 Year Post

GAS-PAIN DIARRHEA

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50

PRE POST Tx 1 Year Post

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25

50

PRE POST Tx 1 Year Post

CONSTIPATION PSYCHOLOGICAL DISTRESS

0

30

60

PRE POST 1 Year Post

Effects of hypnotherapy on colonic motility

Sometimes, it is more important to know what kind of patient has the disease, than what kind of disease the patient has.

Sir William Osler (1849-1919)