Flask shaped ulcers in colon is caused by:-
Amoebiasis: M/C 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.
Giardia lamblia
Entamoeba histolytica
H. Pylori
Enterobius vermicularis
NEET 2019