1. Introduction -- 2. Normal features -- 3. Assessment of abnormalities : diagnostic signposts -- 4. Infective colitis -- 5. Ulcerative colitis -- 6. Crohn's disease -- 7. Ileonal pouch pathology -- 8. Pseudomembranous colitis -- 9. Microscopic colitis : collagenous colitis, lymphocytic colitis and their variants -- 10. Ischaemic colitis -- 11. Iatrogenic disease -- 12. The differential diagnosis of inflammatory bowel disease -- 13. Disorders of motility -- 14. Neoplasia in the colon and rectum and its classification -- 15. Polyps -- 16. The diagnosis of malignancy -- 17. Dysplasia in inflammatory bowel disease -- 18. Malignant tumours -- 19. Anal biopsy -- 20. Miscellaneous conditions.