colectomy (n.)

"large intestine," late 14c., from Latin colon, Latinized form of Greek kolon (with a short initial -o-) "large intestine," which is of unknown origin.

word-forming element meaning "surgical removal," from Latinized form of Greek -ektomia "a cutting out of," from ektemnein "to cut out," from ek "out" (see ex-) + temnein "to cut" (from PIE root *tem- "to cut").