Irritable bowel syndrome (IBS)

Dr. Abdulrahman Aljebreen

To know the ◦pathophysiology, ◦clinical features and ◦how to diagnose and ◦How to manage patients with IBS.

Objectives

It is a chronic or recurrent abdominal pain, altered bowel habits, and bloating, with the absence of structural or biochemical abnormalities to explain these symptoms.

IBS is part of a broader group of disorders known as functional gastrointestinal disorders.

Introduction

It has a prevalence of 12% among adults worldwide.

70% are women. Young (peak at 30-40s). Psychopathology:

◦ High prevalence of psychiatric disorders (anxiety and depression were the most common).

Only 25% of persons seek medical care.

Epidemiology

It is characterized by

Abdominal pain, bloating and bowel habits changes (diarrhea or

constipation)

Pathophysiology

Stress (physical or

psychological)Food (high fat

meal)

Balloon distension studies

Pain during transit of food or gas

60% psychiatric history

Physical or Sexual abuse

High serotonin levels

Infection and Inflammation:◦ inflammation of the enteric mucosa or neural plexuses initiates

symptoms associated with IBS with an increase in pro-inflammatory cytokines.

◦ relationship between an attack of gastroenteritis and IBS. Other events such as trauma, hysterectomy and food

allergy were also reported to precede IBS symptoms.

What increases visceral sensitivity?

≥ 12 wks (not necessary to be consecutive) in the preceding 12 months of abdominal discomfort or pain that has at least 2 of the following:◦ Relief by defecation◦ Onset associated with change in the stool frequency.◦ Onset associated with a change in the form of stool.

Symptoms that cumulatively support the IBS Dx:◦ Abnormal stool frequency (>3 BM/day or <3BM/ week).◦ Abnormal stool form (lumpy/hard or loose/watery)◦ Abnormal stool passage (straining, urgency or feeling of incomplete

evacuation)◦ Passage of mucus◦ Bloating or feeling of abd distension.

ROME 2 Criteria

Long history with relapsing and remitting course. Exacerbation triggered by life events Variability of symptoms Association with symptoms in other organ systems. Coexistence of anxiety and depression Conviction of the patient that the disease is caused by

“popular” concerns (e.g. allergy, food additives, pollution).

Clinical features supporting IBS Dx

IBS is not necessarily diagnosis of exclusion. Need a very good history (Rome 2 criteria + other

clinical features suggestive of IBS) Ask about Alarm symptoms that suggest other serious

diseases.

Diagnosis

Ask about Alarm symptoms that suggest other serious diseases◦ PR bleeding◦ Weight loss◦ Family history of cancer.◦ Fever◦ Anemia◦ Onset >45 years of age◦ Progressive deterioration◦ Steatorrhea◦ dehydration

Alarm symptoms

A firm diagnosis of irritable bowel syndrome based on ◦ validated symptom criteria, ◦ the absence of alarming symptoms, and ◦ a normal physical examination, coupled with

limited relevant diagnostic testing is reassuring to patients.

Labs (CBC, ESR, stool analysis for occult blood and sometimes LFT/urine analysis…etc

US abdomen?? Sigmoidoscopy?? Colonoscopy??

Diagnosis

There is no cure, but effective management may lessen the symptoms.

The therapeutic attitude of the physician during the first interview is of paramount importance.

He should acknowledge the distress caused by the illness.

Build an atmosphere of confidence and trust. Allow sufficient time. Explain to patient that he does not have a serious

disease, however he has a chronic illness characterized by “sensitive gut” which can reacts excessively to food and mood.

Management

Reassurance Identification of psychosocial stressors

should lead to supportive advice and lifestyle modification.

Patients generally seek dietary advice but specific diets or elimination diets have not been proven effective.

Fatty food? if diarrhea? If constipated? If bloating? Exercise?

Non-pharmacological treatment

Oral fiber supplementation has been widely recommended as therapy for IBS

Fiber supplementation results in softer wetter, bulkier stool, which can promote colonic peristalsis and ease defecation.

Controlled trials suggest that fiber supplements are effective for the constipation symptoms of IBS, but not for pain or diarrhea.

Fiber supplements

A rational approach to treating the irritable bowel syndrome uses the patient's symptoms as a guide.◦ Pain predominant IBS◦ Constipation predominant IBS◦ Diarrhea predominant IBS

Nonspecific bowel-directedtherapy

Abdominal pain:◦ Anticholinergics (Buscopan)◦ Calcium antagonists (dicetel)◦ Antidepressents (elavil)

Bloating:◦ Domperidone, Simethicone

Constipation:◦ High-fibre diet, metamucil

Diarrhea:◦ Antimotility or binding agents

Common medical treatments for ABCDs of IBS

Serotonin has been implicated in the modulation of visceral nociception, especially through the 5-HT3 and 5-HT4 pathways.

Two new agents — alosetron, a 5-HT3–receptor antagonist, and tegaserod, a 5-HT4 agonist — have been shown to diminish visceral sensitivity to rectal distention in women who have diarrhea as the predominant symptom of IBS and in those who have constipation as the predominant symptom, respectively.

The IBS is a common disorder that has a pronounced effect on the quality of life and that accounts for a large proportion of health care costs.

Common pitfalls in diagnosing and treating this disorder include ◦ unnecessary repetition of tests, ◦ failure to establish trust in the physician–patient

relationship, and◦ failure to provide the patient with realistic expectations

regarding the efficacy of medications.

In conclusion

A concise diagnostic evaluation and prompt institution of symptom-guided therapy can help alleviate the pain and suffering experienced by patients with IBS.

Summary