diverticulectomy Excision of a diverticulum. A diverticulum refers to a small sac-like structure that sometimes forms in the walls of the intestines where diverticula can trap particles of food (especially small seeds and undigested grains) and become very inflamed and painful (this condition is called diverticulitis). As a person ages, pressure ... Found on http://www.wordinfo.info/words/index/info/view_unit/658/