What are the recommended stool tests and treatment options for a patient with ulcerative colitis?

Recommended Stool Tests and Treatment Options for Ulcerative Colitis

For patients with ulcerative colitis, stool testing should include fecal calprotectin, fecal lactoferrin, and stool testing for Clostridioides difficile and other enteric pathogens, with treatment decisions guided by biomarker results and symptom severity. 1

Diagnostic Stool Testing

Initial Workup

• Fecal calprotectin is a primary biomarker for assessing inflammation in UC, with a cutoff of >150 μg/g indicating active inflammation 1
• Fecal lactoferrin serves as another neutrophil-derived marker that correlates well with histological inflammation 1, 2
• Stool testing for Clostridioides difficile and other enteric pathogens is essential to rule out infectious causes, especially in patients with elevated biomarkers and disease-related symptoms 1

Interpretation of Results

• Fecal calprotectin <150 μg/g suggests minimal inflammation and can rule out active inflammation in patients in symptomatic remission 1, 3
• In patients who have recently achieved symptomatic remission after treatment adjustment, a lower cutoff of <50 μg/g may be preferred to detect endoscopic improvement 1, 3
• Normal fecal lactoferrin correlates with absence of histological inflammation 2, 4

Treatment Algorithm Based on Biomarkers and Symptoms

Moderate to Severe Symptoms

• For patients with moderate to severe symptoms and elevated biomarkers (fecal calprotectin >150 μg/g, elevated fecal lactoferrin, or elevated CRP), treatment adjustment can be made without endoscopic assessment 1
• First-line therapy for moderate to severe UC includes:
  • Biologic agents such as infliximab (5 mg/kg IV at 0,2, and 6 weeks, then every 8 weeks) 5, 6
  • Consideration of other biologics targeting different inflammatory pathways if needed 6, 7

Mild Symptoms

• For patients with mild symptoms and elevated biomarkers, endoscopic assessment is suggested before treatment adjustment 1
• For patients with mild symptoms and normal biomarkers, endoscopic assessment is still recommended, though repeat biomarker measurement in 3-6 months may be a reasonable alternative 1
• First-line therapy for mild to moderate UC:
  • Oral mesalamine (2.4-4.8 g daily for induction, 2.4 g daily for maintenance) 8, 6
  • Topical 5-ASA drugs for proctitis 9, 7

Patients in Remission

• For patients in symptomatic remission, biomarker monitoring every 6-12 months is recommended 3
• If biomarkers are elevated despite symptomatic remission, repeat measurement in 3-6 months is suggested before proceeding to endoscopy 1, 3
• If biomarkers remain elevated on repeat evaluation, endoscopic assessment is warranted 1, 3

Monitoring Strategy

Frequency of Testing

• Fecal calprotectin should be repeated every 6-12 months in patients in symptomatic remission 3
• For patients being treated for active symptoms, testing every 2-4 months is recommended 3
• In patients with elevated biomarkers but sustained symptomatic remission, repeat measurement in 3-6 months before proceeding to endoscopy 1, 3

Special Considerations

• Biomarkers may be less accurate in detecting endoscopic inflammation in patients with ulcerative proctitis or limited segmental disease 1
• Both fecal calprotectin and lactoferrin may be elevated due to non-intestinal sources of infection or inflammation, requiring careful interpretation 1, 4
• Biomarkers have no role in dysplasia detection and surveillance, which requires endoscopic evaluation 1

Treatment Approach Based on Disease Severity

Induction of Remission

• Mild to moderate disease: Oral and topical 5-ASA drugs 8, 6
• Moderate to severe disease: Combination of oral and topical 5-ASA drugs with or without corticosteroids 9, 6
• Severe disease requiring hospitalization: Intravenous steroids; if refractory, consider calcineurin inhibitors or TNF-α antibodies like infliximab 5, 9

Maintenance of Remission

• Mild to moderate disease: Oral mesalamine 2.4 g daily 8, 6
• Moderate to severe disease previously requiring biologics: Continue biologic therapy at maintenance dosing 5, 6

By using this algorithmic approach to stool testing and treatment selection, clinicians can optimize outcomes for patients with ulcerative colitis while minimizing unnecessary procedures and inappropriate medication use.