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)
References:
AGA 2022. https://linkinghub.elsevier.com/retrieve/pii/S0016-5085(22)00390-0
AAFP 2012. https://www.aafp.org/afp/2012/0901/p419.html
CFP
2015. Low FODMAP. http://www.cfp.ca/content/61/8/691
J Neurogastroenterol Motil 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5383110/