Which combining form denotes the colon?

The combining form that denotes the colon is "colon/o." This combining form is specifically used in medical terminology to refer to the colon, which is a major part of the digestive system, responsible for the absorption of water and the formation of feces. In various medical terms, "colon/o" is frequently used before suffixes to indicate conditions, procedures, or anatomy directly related to the colon. For example, "colonoscopy" refers to the procedure used to examine the interior of the colon.

The other options represent different anatomical structures or tissues: "ren/o" pertains to the kidneys, "my/o" relates to muscle tissue, and "gastr/o" refers to the stomach. Understanding these combining forms aids in grasping the broader context of medical terminology.