What is the recommended frequency for follow-up colonoscopy and calprotectin level checks in a patient with ulcerative colitis?

Follow-Up Colonoscopy and Calprotectin Monitoring in Ulcerative Colitis

For surveillance colonoscopy, begin at 8 years after symptom onset, then perform every 1-2 years for high-risk patients (pancolitis, active inflammation, pseudopolyps, or family history of colorectal cancer) or every 3-4 years for low-risk patients; for calprotectin monitoring, check approximately every 3-6 months after treatment initiation to assess mucosal healing, then use as needed to monitor disease activity in stable patients. 1

Surveillance Colonoscopy Schedule

Initial Screening Colonoscopy

• Perform a screening colonoscopy 6-8 years after first symptoms to establish disease extent and begin risk stratification 1
• This timing is critical because up to 22% of patients who develop colorectal cancer do so before commencing surveillance (reduced to 15% when excluding PSC patients) 1

Risk Stratification at First Surveillance

At 8 years from disease onset, stratify patients into risk categories based on four factors (1 point each): 1

• Pancolitis (versus left-sided or distal disease)
• Endoscopic and/or histological inflammation
• Pseudopolyps
• Family history of colorectal cancer

Risk categories: 1

• Low-risk: 0-2 points → Colonoscopy every 3-4 years
• High-risk: 3-4 points → Colonoscopy every 1-2 years

Special Circumstances

• Primary sclerosing cholangitis (PSC): Begin surveillance immediately at PSC diagnosis, as cancer risk is 5-fold higher and occurs earlier (median 2.9 years into disease course) 1
• Proctitis only (no other risk factors): No regular surveillance required due to minimally increased cancer risk 1
• If no intraepithelial neoplasia (IEN) or inflammation in two consecutive surveillance colonoscopies: May increase interval (e.g., from every 1-2 years to every 3-4 years) 1

Quality Considerations for Surveillance

• Perform surveillance colonoscopies during remission when possible, as active inflammation can be misinterpreted as intraepithelial neoplasia 1
• Ensure adequate bowel preparation, as quality significantly affects lesion detection rates 1
• Adequate withdrawal time correlates with neoplasia detection 1

Calprotectin Monitoring Schedule

Initial Treatment Monitoring

Check faecal calprotectin approximately 3-6 months after treatment initiation to determine mucosal healing in patients who clinically respond to medical therapy 1

Ongoing Monitoring in Stable Patients

Use a multimodal approach combining: 1

• Clinical index (partial Mayo or Simple Clinical Colitis Activity Index)
• Hemoglobin and C-reactive protein
• Faecal calprotectin
• Colonoscopy or sigmoidoscopy with histology (at surveillance intervals)

Frequency depends on: 1

• Current therapy
• Duration of remission
• Local resource availability

Calprotectin Thresholds for Action

Faecal calprotectin >200 μg/g: Trigger discussion about lower gastrointestinal endoscopy 1

Faecal calprotectin 100-200 μg/g: In an otherwise well patient, repeat test within a reasonable timeframe; further increase indicates potential treatment complications 1

Faecal calprotectin <100 μg/g: Associated with lower probability of clinical relapse 1

Correlation with Disease Activity

• Calprotectin correlates well with clinical, endoscopic, and histological disease activity 1
• Values <250 μg/g are associated with endoscopic and histological remission and protection against hospitalization or colectomy 1
• Threshold of 187 μg/g is predictive of active disease by UCEIS scoring 1

Important Caveats and Pitfalls

False Positives with Calprotectin

Inflammatory polyps can cause persistently elevated calprotectin (>150 μg/g) without active disease 2

• Consider this before escalating to immunosuppressive or biologic therapy
• Endoscopy may show Mayo score=0 with no histological activity despite high calprotectin
• Multiple small inflammatory polyps are particularly associated with this phenomenon 2

Surveillance Colonoscopy Safety

• Colonoscopy is safe even during severe attacks and can help postpone immediate surgical intervention 3
• However, surveillance should ideally be performed during remission for optimal dysplasia detection 1

Integration with Cancer Surveillance

• The colorectal cancer risk after 20 years of disease is 4.5%, with 1.7-fold higher risk compared to general population 4
• Surveillance colonoscopy improves 5-year cancer-related survival to 100% versus 74% in non-surveillance groups 1
• Cancers are detected at earlier stages in surveillance programs 1

Monitoring Frequency Adjustments

Every 3 months in first year post-surgery, then every 6-12 months thereafter for post-operative patients, depending on recurrence risk 1

Every 3-12 months for laboratory monitoring (complete blood count, liver profile, renal function) to detect treatment side effects 1