Should I undergo a workup for Inflammatory Bowel Disease (IBD)?

Workup for Inflammatory Bowel Disease (IBD)

If you have persistent gastrointestinal symptoms such as chronic diarrhea, abdominal pain, rectal bleeding, or weight loss, you should undergo a workup for IBD, particularly if symptoms have lasted more than 4 weeks and you are between 16-40 years old. 1

Initial Assessment

Symptoms that Warrant IBD Workup

• Rectal bleeding plus one or more of:
  • Abdominal pain
  • Change in bowel habit
  • Weight loss
  • Iron deficiency anemia
• Persistent diarrhea (>4 weeks)
• Nocturnal symptoms
• Unexplained weight loss
• Family history of IBD

Initial Laboratory Testing

1. Fecal Calprotectin - This is the cornerstone screening test for suspected IBD 1, 2

   • <100 μg/g: IBD unlikely, consider IBS
   • 100-250 μg/g: Consider repeat testing or routine referral to gastroenterology

   • 250 μg/g: Refer urgently to gastroenterology

2. Basic Blood Tests

   • Complete blood count (to assess for anemia and inflammation)
   • C-reactive protein (CRP) - more sensitive for acute inflammation
   • Erythrocyte sedimentation rate (ESR) - better for chronic inflammation
   • Celiac disease screening
   • Iron studies (ferritin and transferrin saturation)

Diagnostic Algorithm

Step 1: Fecal Calprotectin Testing

Fecal calprotectin is particularly useful in patients aged 16-40 with chronic diarrhea to differentiate between IBD and IBS, with a high negative predictive value 1. It helps avoid unnecessary invasive procedures in those with functional symptoms.

Step 2: If Calprotectin is Elevated (>250 μg/g)

1. Exclude Infectious Causes

   • Stool culture
   • C. difficile toxin testing
   • Ova, cysts, and parasites examination

2. Refer for Endoscopic Evaluation

   • Ileocolonoscopy with biopsies is the reference standard for IBD diagnosis 1, 2
   • Biopsies should be taken from both inflamed and uninflamed segments

Step 3: Additional Imaging (Based on Clinical Presentation)

• Small Bowel Imaging - Especially important if Crohn's disease is suspected:
  • MR enterography
  • CT enterography
  • Small bowel ultrasound

Special Considerations

When to Suspect IBD vs. IBS

• IBD typically presents with objective signs of inflammation (elevated calprotectin, CRP)
• IBS symptoms often fluctuate and lack objective inflammatory markers
• In patients with IBD-like symptoms but normal inflammatory markers, consider functional GI disorders 1

Pitfalls to Avoid

1. Relying solely on symptoms - Up to 20% of patients with IBD may have overlapping functional symptoms that mimic disease activity 1
2. Missing extraintestinal manifestations - IBD can affect joints, skin, eyes, liver, and other organs 3
3. Inadequate assessment of disease extent - Both small bowel and colon should be assessed in suspected Crohn's disease 2
4. Failure to exclude other causes - Conditions like microscopic colitis, bile acid malabsorption, and celiac disease can mimic IBD symptoms 1

Red Flags Requiring Urgent Assessment

• Severe abdominal pain
• Significant weight loss
• Fever
• Severe rectal bleeding
• Signs of bowel obstruction

Follow-up After Diagnosis

If IBD is diagnosed, regular monitoring is essential:

• Periodic assessment of disease activity using calprotectin (every 3-6 months)
• Monitoring for nutritional deficiencies
• Surveillance for complications

Remember that early diagnosis and treatment of IBD can significantly improve outcomes and quality of life by preventing disease progression and complications.