W Smalley et al. Gastroenterol 2019; 157: 851-54. Full Text Link: AGA Clinical Practice Guidelines on the Laboratory Evaluation of Functional Diarrhea and Diarrhea-Predominant Irritable Bowel Syndrome in Adults (IBS-D)
Clinical support tool on pg 855, Patient Summary 856-57, and Technical Review 859-80.
These guidelines/recommendations (listed below) do NOT apply to patients with any of the following:
- Alarm features such as gross blood, weight loss, anemia, and hypoalbuminemia
- Family history of of IBD, colon cancer, or celiac disease
- Travel to areas with high prevalence of infectious diarrhea
- Immune suppression
- Ingestion of medications or substances known to cause diarrhea
Statement | Strength of recommendation | Quality of evidence |
---|---|---|
Recommendation 1: In patients presenting with chronic diarrhea, the AGA suggests the use of either fecal calprotectin or fecal lactoferrin to screen for IBD. | Conditional | Low |
Recommendation 2: In patients presenting with chronic diarrhea, the AGA suggests against the use of ESR or CRP to screen for IBD. | Conditional | Low |
Recommendation 3: In patients presenting with chronic diarrhea, the AGA recommends testing for Giardia. | Strong | High |
Recommendation 4: In patients presenting with chronic diarrhea with no travel history to or recent immigration from high-risk areas, the AGA suggests against testing stools for ova and parasites (other than Giardia). | Conditional | Low |
Recommendation 5: In patients presenting with chronic diarrhea, the AGA recommends testing for celiac disease with IgA-tTG and a second test to detect celiac disease in the setting of IgA deficiency | Strong | Moderate |
Recommendation 6: In patients presenting with chronic diarrhea, the AGA suggests testing for bile acid diarrhea. | Conditional | Low |
Recommendation 7. In patients presenting with chronic diarrhea, the AGA makes no recommendation for the use of currently available serologic tests for diagnosis of IBS | None | Knowledge gap |
For recommendation #6, the authors note that tests for bile acid mediated diarrhea in the U.S. include total bile acid in a 48-hour stool collection and serum fibroblalt growth factor 19.
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