Final answer:
The diagnostic term used to refer to a dilated or varicose (twisted) internal and/or external vein in the rectum is hemorrhoids.
Step-by-step explanation:
The diagnostic term used to refer to a dilated or varicose (twisted) internal and/or external vein in the rectum is hemorrhoids. Hemorrhoids occur when there is increased pressure on the veins in the rectal area, causing them to enlarge and become painful.