1. Dr. Angus Lee SET 1 General Surgery

2. Burrill Crohn, an American Gastroenterologist, with his 2 other colleagues first described “Terminal ileitis” in 1932

3. Epidemiology of IBD Incidence 2-15/100, 000 Prevalence 40-80/100,000 More common in developed countries; higher SES More common in Jewish population; less common in Asian population Presentation commonly at younger age ~ 20s; but can occur at any age First degree relative with Crohn’s : ~ 10% lifetime risk Monozygotic twins: 58% for Crohn’s; 6% for UC

4. Pathogenesis Complex Immunological Genetic and environmental factors eg. IBD1 gene encodes NODS2 which regulates intestinal epithelial cells immunity has been implicated Role of smoking: increases risk 2x in Crohn’s but lower risk in UC

5. How to differentiate Crohn’s and UC? Direct visualisation by endoscopy Histological diagnosis Radiological appearance Antibodies: anti – Saccharomyces cerevisiae (ASCA) for Crohns; antineutrophil cytoplasmic antibody (p- ANCA) for UC

6. Pathological features

7. Distribution Crohn’s UC SB alone ~30-35% Colon alone ~ 25-35% Both ~ 30-50% Perianal ~50% Stomach and duodenum 5% Rectum 50% Proctosigmoid 30% Extending beyond splenic flexure 20%

8. GI/ Liver secrets. McNally 4 th ed

9. Crohn’s

16. Complications UC Crohn’s Perforation Haemorrhage Toxic megacolon Carcinoma Perforation Stricture Fistula Perianal complication Malnutrition Vit B12 deficiency Stones: renal; gallbladder

17. Severity of UC

18. Medical management: 5- ASA Depends on extent of disease and severity 5-aminosalicylate (5- ASA) eg. Sulfasalazine; mesalazine; olsalazine Sulfasalazine: azo bond to sulfapyridine; bond broken down by colonic bacteria; therefore releasing active sulfasalazine Side effects relate to sulphonamide component Olsalazine: two 5 ASA Mesalazine: enteric coating of 5 ASA; coating dissolves in TI Distal disease --- 5 ASA enema/ suppository (enema can only reach up to splenic flexure at most) More extensive disease --- oral preparation

19. Use of steroid Route: PR suppository; enema; foam; oral; IV Generally effective in inducing remission; not so effective in maintaining remission Moderate cases: oral steroid Severe cases: IV hydrocort

20. Immunosuppressive drugs Azathioprine 6- mercaptopurine Cyclosporin Monoclonal antibody: targettingTNF alpha eg. Infliximab -useful for both ileal and colonic Crohn’s - high response rate in severe cases and patients with fistulae.

22. 70% of Crohn’s require surgery Surgery in UC can be potentially curative

23. Indication Crohn’s UC Failure of medical management Obstruction Fistulae Abscess Haemorrhage Perforation Growth retardation Cancer Failure of medical management Toxic megacolon Haemorrhage Perforation Cancer - <1% from 10 years of onset - 10-15% second decade - >20% third decade - ~ 1% increase of incidence after 10 years of colitis

24. Surgical objectives for complications of Crohn’s disease Preoperative Objectives Maximize or exhaust nonsurgical treatment options prior to surgery Surgical intervention should be limited to the treatment of symptomatic complications of Crohn’s disease Evaluate nutritional status prior to surgery Consider supplemental nutrition to improve nutritional parameters prior to surgery Intraoperative Objectives Spare bowel length Utilize alternative strategies to resection when appropriate to preserve sufficient length of the remaining bowel; minimize short bowel syndrome Preserve ileocaecal valve if possible Biopsy any suspicious ulcers or mucosa for malignancy

25. Stricturoplasty

26. Fistulae Classification: Spontaneous vs postoperative Internal vs external SNAP approach Sepsis; Nutrition; Anatomy; Plan

27. Choices of operation in UC Emergency Elective Subtotal colectomy and ileostomy Proctocolectomy and permanent ileostomy Proctocolectomy and ileal pouch Colectomy and ileal rectal anastomosis Proctocolectomy and continent ileostomy

30. Pouchitis Cumulative incidence: 15-53% double risk if PSC Treatment: ciprofloxacin and metronidazole VSL 3 probiotic was shown to be effective in maintaining remission in ~85% of pouchitis