The suffix "-stomy" refers to the surgical creation of an opening. This is commonly used in medical terms to describe procedures where an artificial opening is made in the body, such as a colostomy or tracheostomy. The other options, "-scopy," refer to procedures involving the use of a scope or instrument to examine or visualize a body part, such as endoscopy or colonoscopy. Therefore, the correct answer is "-stomy" as it specifically relates to the creation of an opening.