Inflammatory Bowel Disease Overview

Inflammatory Bowel Disease (IBD)

• IBD encompasses Crohn's disease and ulcerative colitis (UC), both chronic conditions with acute exacerbations.
• Symptoms are often similar (diarrhea, weight loss, abdominal pain, fever, fatigue), but differ in presentation.

Crohn's Disease

• Common symptoms include diarrhea and cramping abdominal pain.
• Small intestinal involvement causes weight loss due to malabsorption.
• Rectal bleeding can occur, but less frequently than in UC.

Ulcerative Colitis (UC)

• Characterized by bloody diarrhea and abdominal pain, ranging from mild cramping to severe constant pain from acute perforations.
• Disease severity varies:
  • Mild: 4 semiformed stools daily with small blood amounts.
  • Moderate: increased stool output (up to 10 stools/day), increased bleeding, systemic symptoms (fever, malaise, mild anemia, anorexia).
  • Severe: bloody diarrhea with mucus, 10-20 stools daily, rapid weight loss, fever, severe anemia, tachycardia, dehydration.

Complications of IBD

• GI Tract: hemorrhage, strictures, perforation (with possible peritonitis), abscesses, fistulas, Clostridium difficile infection (CDI), toxic megacolon.

• Toxic megacolon is more common in UC and risks perforation, potentially requiring emergency colectomy.

• Perineal abscesses and fistulas are common in Crohn's disease.

• CDI frequency and severity are higher in IBD patients.

• IBD increases colorectal cancer (CRC) risk. Crohn's disease patients have higher small intestinal cancer risk.

• Regular cancer screening is crucial for IBD patients.

• Systemic: multiple sclerosis, ankylosing spondylitis (inflammation-related, improving with IBD improvement); malabsorption, liver disease (primary sclerosing cholangitis), osteoporosis.

• Primary sclerosing cholangitis can lead to liver failure, necessitating routine liver function tests.

• Bone density scans are essential for IBD patients, baseline and every 2 years.

Diagnostic Studies

• Diagnosing IBD involves ruling out similar conditions and differentiating Crohn's from UC.
• Early Crohn's symptoms mimic Irritable Bowel Syndrome (IBS).
• Diagnostic tools assess disease severity and complications:
  • Complete Blood Count (CBC) often reveals iron deficiency anemia due to blood loss.
  • High white blood cell count (WBC) suggests toxic megacolon or perforation.
  • Decreased serum electrolytes (sodium, potassium, chloride, bicarbonate, magnesium) from fluid and electrolyte losses.
  • Hypoalbuminemia (low albumin) indicates severe disease due to poor nutrition or protein loss.
  • Increased erythrocyte sedimentation rate, C-reactive protein, and WBCs signify inflammation.
  • Stool analysis for blood, pus, mucus; cultures for infection.
  • Imaging (double-contrast barium enema, small bowel series, transabdominal ultrasound, CT, MRI).
  • Colonoscopy examines the entire large intestine (and sometimes the distal ileum) enabling assessment of inflammation, ulcerations, pseudopolyps, strictures, and biopsies for diagnosis.
  • Capsule endoscopy may be needed for Crohn's disease in the small intestine, since colonoscopies only reach the distal ileum.