<prompt> Flask shaped ulcers in colon is caused by:-Giardia lambliaEntamoeba histolyticaH. PyloriEnterobius vermicularis  <response>: Amoebiasis: MC pathogenic amoeba in humans - E. histolytica Trophozoites of E. histolytica attaches to submucosa of cecum ascending Colon to produce FLASK SHAPED ULCERS and causes abscess. 