The Colon

1. The Colon

4. BLOOD SUPPLY OF THE COLON

5. Physiological Function • Fluid re-absorption • reabsorbs 1.5-2 litres per day • Storage • Elimination • Enteric flora

6. Symptoms & Signs in Colon Diseases

7. Symptoms of Colonic Diseases • Diarrhoea • Constipation • Incontinence • Flatulence • Pain • Blood per rectum • Systemic symptoms

8. ALARM SYMPTOMS • Later age of onset • Weight loss • Anaemia • Blood loss • Nocturnal symptoms • Family history colon cancer

9. Origin of Abdominal Pain

10. Common causes of lower gastrointestinal bleeding • Anatomical • Diverticulosis • Vascular • Haemorrhoid • Angiodysplasia • Ischemic • Radiation-induced telangiectasia • Inflammatory • Infectious • Idiopathic inflammatory bowel disease • Neoplastic • Polyp • Carcinoma • Others • Ulcer • Post biopsy or polypectomy

11. Vascular Ectasia

12. Signs of Colonic Disease • Tenderness • Rebound, guarding • Mass • Systemic signs • Digital Rectal Examination

13. Investigations • Radiology • Endoscopy

14. Barium Enema

15. Barium Enema

16. Barium Enema

17. Sigmoidoscopy

18. Endoscopy

19. Diseases of the Colon

20. Diverticular Disease

24. Diverticular Disease • Very common - >50% in over 50’s • 90% asymptomatic • Symptomatic >10% • Haemorrhage 25% sts massive • Diverticulitis 75%

25. NATURAL HISTORY OF DIVERTICULAR DISEASE

26. Symptomatic Simple Diverticular Disease • Colicky LIF pain • Constipation • STS rectal bleeding • Treatment: • Fibre • Stool softeners

28. Complicated Diverticular Disease • Mucosal inflammation – diverticular colitis • Subserosal inflammation – diverticulitis • Abscess • Bleeding • Obstruction • Perforation/fistula

30. ISCHEMIC COLITIS • Elderly arteriopaths • CV risk factor profile • Often after hypotensive episode • Pain first, often mild • Bleeding & diarrhoea

31. BLOOD SUPPLY OF COLON

32. Investigations • PFA – “thumb printing” • Endoscopy • rectal sparing • segmental involvement • CT scanning

33. ISCHEMIC COLITIS

34. Ischemic Colitis

35. Management • Conservative approach • iv fluids, treat anaemia • Nutrition • 10% later stricture • Surgery for gangrene of colon

36. C. difficile • Anaerobic gram-positive, spore-forming, toxin-producing bacillus 1935 • 1978 - c. diff identified as cause of antibiotic related diarrhoea – mostly clindamycin • fecal-oral route • Toxins A & B • Recently hypervirulent strain – 027 • Exponential increase

38. RISK FACTORS • antibiotic use • hygiene/handwashing • hospitalisation/overcrowding • advanced age • PPIs • GI surgery • enteral feeding

39. ANTIBIOTICS & CDAD

40. CLINICAL MANIFESTATIONS • Spectrum: asymptomatic to toxic megacolon • Watery diarrhoea cardinal feature • Offensive • Often prominent systemic features • Pseudomembranes on endoscopy

46. MANAGEMENT • Stop antibiotics • Infection control • Supportive therapy • Treat on suspicion • Metronidazole or vancomycin • Rarely surgery • Relapses

47. Inflammatory Bowel Disease • Ulcerative colitis • Crohn’s disease • Microscopic colitis • Lymphocytic colitis • Collagenous colitis

48. Ulcerative Colitis •  Ulcerative colitis is characterized by recurring episodes of inflammation limited to the mucosal layer of the colon. It almost invariably involves the rectum and may extend in a proximal and continuous fashion to involve other portions of the colon

49. Crohn’s Disease Crohn's disease is characterized by transmural rather than superficial mucosal inflammation and by skip lesions rather than continuous disease. The transmural inflammatory nature of Crohn's disease can lead to stricture formation, microperforations and fistulae. Crohn's disease may involve the entire gastrointestinal tract from mouth to perianal area.

50. Comparisons of various factors in Crohn's disease and ulcerative colitis