Surgical removal of part or all of the colon. colectomy. surgical excision of part or all of the colon, performed to treat cancer of the colon, diverticulitis, or severe chronic ulcerative colitis. For several days before surgery a low-residue diet is prescribed.
Airborne Rangers are a direct-action force of raiders. The U.S. Army website describes a regiment of Airborne Rangers as a lethal, agile and flexible force.. They must maintain a state of combat readiness and, when deployed, are asked to complete complex, often dangerous missions.
Both the army rangers and the Green Berets are Special Forces groups in the US army. Both are considered elite members of the US armed forces and have specialized functions. Both, the rangers and the Green Berets, have served the interests of the US outside the country.