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 Intestinal structures Embryological origin Spinal segmentsPain location Oesophagus, gastric, duodenal ForegutT5-6 to T8-9Epigastric Small intestine to transverse colon MidgutT8-11 to L1Peri-umbilical Transverse to recto-sigmoid HindgutT11 to L1Suprapubic

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

17. Sigmoidoscopy

18. Endoscopy

19. Diseases of the Colon

20. Diverticular Disease

24. 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 Frequently associated Occasionally associated Rarely associated fluoroquinolonesmacrolidesaminoglycosides clindamycintrimethoprimtetracyclines Penicillin (broad spectrum) sulphonamideschloramphenicol cepalosporinsmetronidazole vancomycin

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 CrohnsUC rectum involveduncommomyes anus involvedyesno TI involvedoftenno colon involvedoftenalways PSCless commonmore commom EndoscopyUlcerscontinuous InflammationTransmuralsuperficial InflammationSkipcontinuous fistulae/stenosesYesno GranulomasOftenno Smokingincreases risklowers risk Surgical curenoyes AppendicectomyNo influenceprotective

51. Crohn’s Disease

53. Distribution of Crohn’s Disease

54. Ulcerative Colitis

56. Crohn’s Disease

58. Ulcerative Colitis

60. Crohn’s Disease

61. Ulcerative Colitis

62. Causes of Diarrhoea in Crohn’s Disease ConsiderationTreatment mucosal inflammationanti-inflammatory Rx bacterial overgrowthantibiotics bile salt diarrhoeacholestyramine bile acid deficiencylow fat diet lactase deficiencyavoid latose short bowellow fat diet internal fistulaesurgery antibiotics (c. diff)treat

66. Colon Carcinoma

67. COLORECTAL CANCER Polyp-dysplasia-cancer sequence –genetic –environmental

69. Clinical Features –Depends on site of tumour –1/3 proximal to splenic flexure –Bleeding –Change in bowel pattern –Fe deficiency anaemia –Pain non-specific –Systemic features late –Metastatic

70. CLINICAL FEATURES Abdominal pain — 44 percent Change in bowel habit — 43 percent Hematochezia or melena — 40 percent Weakness — 20 percent Anemia without other gastrointestinal symptoms — 11 percent Weight loss — 6 percent

71. Investigation Sigmoidoscopy/Colonoscopy Biopsy Barium studies CT scanning

74. Colon Carcinoma

76. Dukes classification Dukes A - limited to bowel wall Dukes B - extends thro’ muscle wall Dukes C - LN involvement - C1 & C2 Dukes D - outside bowel wall

78. Treatment Surgery Chemotherapy Radiotherapy

81. Screening To detect cancer at treatable stage Age > 50 years Targeted screening

82. Screening Faecal occult blood Sigmoidoscopy Colonoscopy Virtual colonoscopy

83. Colon Polyp

85. Virtual Colonoscopy