ostomy vs surgical operation

ostomy and surgical operation both are nouns.

Word	Noun	Adjective	Verb	Adverb
ostomy	Yes	No	No	No
surgical operation	Yes	No	No	No

As nouns, surgical operation is a hypernym of ostomy; that is, surgical operation is a word with a broader meaning than ostomy:

ostomy: surgical procedure that creates an artificial opening for the elimination of bodily wastes
surgical operation: a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body

Other hypernyms of ostomy include operation, surgery, surgical procedure, surgical process.

ostomy (noun)	surgical operation (noun)
surgical procedure that creates an artificial opening for the elimination of bodily wastes	a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body