-stomy

1.
a combining form used in the names of surgical operations that involve the establishment of an artificial opening into or between the part or parts specified by the initial element:
gastrostomy.
Origin
< Greek -stomia, derivative of stóma mouth. See -stome, -y3
British Dictionary definitions for -stomy

-stomy

combining form
1.
indicating a surgical operation performed to make an artificial opening into or for a specified part: cytostomy
Word Origin
from Greek -stomia, from stoma mouth
-stomy in Medicine

-stomy suff.
A surgical operation in which an artificial opening is made into an organ or part: colostomy.