1. Inflammatory Bowel Disease Ulcerative colitis (UC) Kristina Blaslov Mentor: A. Žmegač Horvat

2. Epidemiology Highest incidence in Europe, United Kingdom, North America Incidence per person-years 2.2–14.3/100,000 Age of onset15–30 & 60–80 Male:female ratio1:1 SmokingMay prevent disease Oral contraceptivesNo increased risk AppendectomyProtective Monozygotic twins6% concordance Dizygotic twins0% concordance

3. Etiology and Pathogenesis Consensus hypothesis: genetically predisposed individuals + exogenous factors + host factors ↓ dysregulated mucosal immune function (modified by specific environmental factors )

4. Pathology Macroscopic features: - mild inflammation - moderate disease - long-standing disease - fulminant disease

5. Microscopic features -process limited to the mucosa and superficial submucosa, with deeper layers unaffected (except in fulminant disease!)

6. Clinical presentation Signs and symptoms: - diarrhea - rectal bleeding - tenesmus - passage of mucus - abdominal pain - other symptoms: anorexia, nausea, vomiting, fever, weight loss

7. Laboratory - rise in acute-phase reactants - erythrocyte sedimentation rate - decrease in hemoglobin - leukocytosis - pANCAs Endoscopy (not in acute phase!) - sigmoidoscopy - colonoscopy Radiology - barium enema

8. Diagnosis relies on the patient's history, clinical symptoms, negative stool examination for bacteria, C. difficile toxin, and ova and parasites; sigmoidoscopic appearance and histology of rectal or colonic biopsy specimens!

9. Extraintestinal manifestations: - dermatologic - erythema nodosum, pyoderma gangrenosum - rheumatologic - peripheral arthritis, ankylosing spondylitis - ocular - conjunctivitis, uveitis/iritis, episcleritis - hepatobiliary - steatosis, PSC - urologic - calculi, ureteral obstruction, fistulas - metabolic bone disorders - low bone mass

10. Treatment

11. Nutritional therapies : - total parenteral nutrition Surgical therapy - indications: intractable disease, fulminant disease, toxic megacolon, colonic perforation, massive colonic hemorrhage, colonic obstruction, colon cancer prophylaxis, colon dysplasia or cancer

12. References: Harrison’s Principles of Internal Medicine, 17 th edition