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What is Characteristic feature of amoebic ulcer -a)  Flask shapedb)  Undermined edgesc)  Rolled up edged)  Punched out and explain in detail?
Amebiasis most frequently involves the cecum and ascending colon, followed in order by the sigmoid, rectum and appendix.
The ulcerative lesions develop undermining of margins of the ulcer due to lytic action of the trophozoites.
Ulcer has a flask shaped with a narrow neck and broad base.