Key Points
- These guidelines apply to the evaluation of the immunocompetent patient with “watery” diarrhea of at least four weeks duration.
- This excludes those patients with bloody diarrhea; diarrhea with signs of fat malabsorption; presentations with alarm features such as weight loss, anemia, and hypoalbuminemia; those patients with a family history of inflammatory bowel disease (IBD), colon cancer, or celiac disease; and those with a travel history to regions with recognized specific diarrhea-related pathogens.
Treatment
Table 1. Summary of Recommendations of AGA Clinical Guideline on the Laboratory Evaluation of Functional Diarrhea and Diarrhea-Predominant Irritable Bowel Syndrome in Adults (IBS-D)
| Recommendation | Strength of recommendation | Quality of evidence |
|---|---|---|
| 1. In patients presenting with chronic diarrhea, AGA suggests the use of stool tests, either fecal calprotectin or fecal lactoferrin to screen for inflammatory bowel disease. | Conditional recommendation | Low quality evidence |
| 2. In patients presenting with chronic diarrhea, AGA suggests against the use of blood tests erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) to screen for inflammatory bowel disease. | Conditional recommendation | Low quality evidence |
| 3. In patients presenting with chronic diarrhea, AGA recommends stool testing for Giardia. | Strong recommendation | High quality evidence |
| 4. In patients presenting with chronic diarrhea with no travel history to or recent immigration from high risk areas, AGA suggests against testing stools for ova and parasites (other than Giardia). | Conditional recommendation | Low quality evidence |
| 5. In patients presenting with chronic diarrhea, AGA recommends testing for celiac disease with IgA tTG and a second test to detect celiac disease in the setting of IgA deficiency. | Strong recommendation | Moderate quality evidence |
| 6. In patients presenting with chronic diarrhea, AGA suggests testing for bile acid diarrhea. | Conditional recommendation | Low quality evidence |
| 7. In patients presenting with chronic diarrhea, AGA makes no recommendation for the use of currently available serologic tests for diagnosis of IBS. | No recommendation | Knowledge gap |
Irritable Bowel Syndrome in Adults (IBS-D) Clinical Decision Support Tool
