Amoebic colitis is an infection of the colon caused by the Entamoeba histolytica parasite. It often causes flask-shaped ulcers in the ascending colon, sigmoid colon, or rectum. The ulcers form as small microulcerations that enlarge over time. Numerous trophozoites can be seen at the ulcer margins. Large ulcers show extensive necrosis with an inflamed, thickened intestinal wall. Complications can include liver abscess, effusions in the pleura or pericardium, or hepatobronchial fistulas. Patients experience abdominal pain, cramping, and bloody diarrhea. Diagnosis involves identifying E. histolytica trophozoites on a PAS stain of

1. Amoebic colitis

2. Amoebic colitis
• Infection of the colon with Entamoeba
histolytica
Morphology
• Sites:
• Ascending colon –the most common
• Sigmoid colon
• Rectum
• appendix

3. • Flask shaped ulcers:
• Early intestinal lesion is microulceration of
mucosa which slowly enlarges.
• Small ulcer with heaped up margin but
extends below the surface n apperars as flask-
shaped.

4. • Numerous trophozoites can be seen at the
margin of dead n viable tissue.
• Large ulcers show extensive liquefactive
necrosis with shaggy appearance.

5. • Ameboma: ameobic infection grossly appears
as a mass. The mucosa becomes thin n
ulcerated.Below this is inflammed n thickened
wall of intestine, which is edematous and
hemorrhagic with exuberant granulation
tissue formation.

6. • Complications
• 1) liver abscess
• 2) effusion;;pleural
• 3) Hepatobronchial fistula
• 4) pericardial effusion

7. • Clinical picture:
• Pain abdomen with cramp
• Diarrhoea, sometimes with blood.
• Diagnosis: PAS stain: trophozoites of
E.Histolytica are stained by PAS and iron
haematoxylin.

11. • Thank you..