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

  • 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)