Lower GIT

1. LOWER
GASTROINTESTINAL
TRACT
Dr. Shameera Begum

2. DIFFERENCE BETWEEN
SMALL INTESTINE
AND
LARGE INTESTINE

3. LARGE INTESTINE
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4. LARGE INTESTINE
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5. SMALL INTESTINE
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6. 6

7. DUODENUM
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8. 8

9. ILEUM
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10. 10

11. COLON
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12.  TB intestine
 Wet gangrene of intestine
 Inflammatory bowel disease
 Crohn disease
 Ulcerative colitis
 Colorectal adenocarcinoma
OVERVIEWOVERVIEW

13. INTESTINAL TUBERCULOSIS
 Causative agent- Mycobacterium tuberculosis
 Mostly affects the ileum or ileocaecal junction
 Intestinal tuberculosis contracted by the drinking of
unpasteurised milk.
 In countries where milk is pasteurized, intestinal TB is caused
by the swallowing of coughed-up infective material in patients
with advanced pulmonary disease

14. MORPHOLOGY OF TUBERCULAR
ULCER
GROSS
-Transverse ulcer in the direction of lymphatics
-multiple and circumferential
- Ulcer leads to fibrosis which cause stenosis and
obstruction

15. TRANSVERSE ULCERS IN TB

16. TB OF COLON

17. 17

18. MICROSCOPY
 CASEATING GRANULOMA
- Shows central caseous necrosis surrounded by
granuloma
- Granuloma composed of epitheloid cells, langhans
giant cells and lymphocytes.
- AFB/ ZN Stain positivity.

19. TB- MICROSCOPY

20. WET GANGRENE OF INTESTINE
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21. 21

22. 22

23. INFLAMMATORY BOWEL
DISEASE

24. CROHN’S DISEASE
 General considerations
 Chronic inflammatory condition of unknown etiology
 Can affect any part of the GIT
 Most commonly involves terminal ileum, ileocaecal valve
and caecum.
 Younger individuals.
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25. CROHN’S DISEASE
 Gross
 Earliest lesion, aphthous ulcer coalesce to form multiple, elongated,
serpentine ulcers along the axis of the bowel.
 Skip lesions
 Cobblestone appearance
 Fissures
 Fistula
 Creeping fat
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26. LOSS OF NORMAL MUCOSAL FOLDS ( LINEAR MUCOSA )
( COBBLESTONE –SHAPED MUCOSA )
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The characteristic of crohn's disease

27. 27

28. THE CHARACTERISTIC OF CROHN'S
DISEASE
 Strictures (stenosis )
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29.  Creeping fat
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The characteristic of crohn's disease

30. CROHN’S DISEASE
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31. ULCERATIVE COLITIS
 Limited to colon and rectum
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32. Gross
Mucosal inflammation and ulceration always
involves rectum and extends proximally in a
continuous fashion to involve colon
 Red or granular appearance of mucosa
Extensive broad based ulcers
Pseudopolyps
 Mural thickening is not present
Serosa is normal
No strictures
Toxic megacolon – medical emergency 32

33. 33
ULCERATIVE COLITIS

34. HEALTHY MUCOSA VS ULCERATIVE
COLITIS
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35. ULCERATIVE COLITIS -CRYPT
ABSCESS
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36. FEATURES THAT DIFFER BETWEEN CROHN
DISEASE AND ULCERATIVE COLITIS
Feature Crohn Disease Ulcerative Colitis
MACROSCOPIC
Bowel region Ileum ± colon Colon only
Distribution Skip lesions Diffuse
Stricture Yes Rare
Wall appearance Thick Thin
MICROSCOPIC
Inflammation Transmural Limited to mucosa
Pseudopolyps Moderate Marked
Ulcers Deep, knife-like Superficial, broad-based
Lymphoid reaction Marked Moderate 36

37. FEATURES THAT DIFFER BETWEEN
CROHN DISEASE AND ULCERATIVE
COLITIS
Feature Crohn Disease Ulcerative Colitis
Fibrosis Marked Mild to none
Serositis Marked Mild to none
Granulomas Yes ( 50%)∼ No
Fistulae/sinuses Yes No
CLINICAL
Perianal fistula Yes (in colonic disease) No
Fat/vitamin
malabsorption
Yes No
Malignant potential With colonic involvement Yes
Recurrence after surgery Common No
Toxic megacolon No Yes
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38. ADENOCARCINOMA OF THE COLON AND
RECTUM
Most common malignancy of the GIT
The peak age incidence is in the sixth to seventh decades.
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39. TWO GENETIC PATHWAYS ARE
INVOLVED
APC/ β – CATENIN PATHWAY
MICROSATELLITE INSTABILITY
PATHWAY
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40. 40

41. Predisposing factors
1. Adenomatous polyps
2. Familial adenomatous polyposis
3. Hereditary non polyposis colonic cancer
4. Long-standing ulcerative colitis
5. Genetic factors; up to a four-fold increase in incidence is
noted among relatives of patients with colon cancer.
6. A low-fiber diet that is high in animal fat; the disease is
less common in much of the Third World, where populations
consume a high-fiber diet that is low in animal fat.
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42. 42

43. MULTIPLE POLYPOSIS. THE POLYPS ARE BENIGN, BUT
EACH OF THE INNUMERABLE POLYPS HAS ABOUT A
1% POTENTIAL FOR MALIGNANT CHANGE.
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44. TYPICAL SITES OF INCIDENCE AND
SYMPOMS OF COLON CANCER

45. COLORECTAL ADENOCARCINOMA -
CHARACTERISTICS
Right Sided growth
 Fungating, large
cauliflower-like, soft and
friable mass projecting
into the lumen
Left Sided growth
 Napkin-ring
configuration, encircling
the bowel wall
circumferentially with
increased fibrous tissue
forming annular ring with
central mucosal
ulceration
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46. Right sided growth - Adenocarcinoma of caecum demonstrates an
exophytic growth pattern.

47. Adenocarcinoma of the rectosigmoid region

48. 48
Right Sided growth Left Sided growth

49. CLINICAL FEATURES
Right Sided growth
 Iron deficiency anaemia
 Fatigue and weakness
Left Sided growth
 Obstruction
 Occult bleeding
 Changes in bowel habits
 Cramping
 Left lower quadrant pain
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50. The barium enema - the classic "apple core” lesion is present, representing an
encircling adenocarcinoma that constricts the lumen.

51. INVASIVE ADENOCARCINOMA OF COLON
SHOWING MALIGNANT GLANDS INFILTRATING
THE MUSCLE WALL.
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