Table 3. American College of Gastroenterology IBS Task Force Recommendations for Diagnostic Testing
Diagnostic Test
Routine blood tests (complete blood count, chemistries, thyroid function, stool ova/parasites)
Celiac disease serology
Abdominal radiological imaging
Colonoscopy Recommendations
NOT recommended in patients with typical IBS symptoms and no alarm features because of a low likelihood of uncovering organic disease (1C)
Recommended in IBS-M and IBS-D (1B)
NOT recommended in patients with typical IBS symptoms and no alarm features (1B)
Recommended if alarm symptoms/signs are present to rule out organic disease Recommended in patients aged ≥ 50 years for routine screening (1C) NOT recommended if no alarm symptoms in patients aged < 50 years with typical IBS symptoms Colonic biopsies are recommended if performing a colonoscopy in IBS-D to rule out microscopic colitis (2C)
Breath testing to rule out lactose intolerance
Breath testing for SIBO
Food allergy testing and exclusion diets
Recommended only if clinical suspicion is high and exclusion diet has failed (1B)
Not routinely recommended due to insufficient data (2C) Not routinely recommended due to insufficient data (2C)
Table 4. Alarm Features
• New onset of symptoms at ≥ 50 years • Unintentional weight loss • Nocturnal diarrhea • Anemia • Bloody stools • Family history of colon cancer, celiac disease or inflammatory bowel disease
