colostomynoun [ C or U ]
/kəˈlɒs.tə.mi//kə.lɑː.stə-/specializedan operation in which the colon (= the lower and bigger part of the bowels) is cut and the cut end joined to a hole in the wall of the abdomen:
She became unable to digest food and needed a colostomy.
a colostomy bag (= container outside the body for body waste after a colostomy)