Irritable Bowel Syndrome (IBS)

General Overview

• ROME IV Diagnostic Criteria

  • Recurrent abdominal pain associated at least 1 day/week in past 3 months (absence of organic disease) associated with ≥2 of

    • Related to defecation

    • Change in stool frequency

    • Change in stool form

  • Diarrhea-predominant, constipation-predominant, vs. mixed presentation

Risks

• Young age

• Female

• Smoking

• Anxiety/Stress

Red Flags

• Unexplained iron-deficiency anemia

• Rectal bleeding

• Nocturnal symptoms or progressive pain

• Weight loss, fever

• Antibiotic use

• Onset >50yo

• Family history of GI disease (IBD, colorectal cancer)

Consider Investigations

• CBC

• Anti TTG Ab, total IgA

  • Rule out celiac

• CRP or fecal calprotectin

  • Rule out IBD, malignancy, parasitic based on risk

Treatment

• Exercise

• Diet

  • Low FODMAP diet

    • Consider lactose/gluten avoidance

  • May keep food diary

  • No evidence for fiber (may consider soluble fiber in constipation - eg. Plantago)

  • No evidence to support allergy testing

• Pharmacological

  • Constipation

    • Psyllium

    • PEG laxatives (conditional, low certainty of eveidence)

    • Linactolide (strong recommendation, high certainty of evidence)

  • Abdominal pain

    • Antispasmodics [dicyclomine 20mg PO QID PRN, hyoscyamine] , TCAs (conditional, low certainty of eveidence)

  • Diarrhea

    • Antidiarrheals (loperamide)

    • Bile acide sequestrants

  • Lack of evidence for probiotics and SSRIs

• Alternative

  • No clear evidence for hypnotherapy, psychotherapy, acupuncture

  • Consider 3-6 capsules of 0.2-0.4mL peppermint oil PO daily (NNT 3)