Final answer:
A drug agent that promotes bowel evacuation is known as a laxative, which helps alleviate constipation and encourages bowel movements.
Step-by-step explanation:
A drug agent that promotes bowel evacuation is known as a laxative. Laxatives are substances that stimulate the muscles of the gastrointestinal tract or increase the bulk of feces, which in turn encourages bowel movements. These agents are commonly used to alleviate constipation, a condition characterized by infrequent or difficult bowel movements. It's essential to consume ample fiber and water in your diet to maintain healthy bowel functions and to avoid reliance on laxatives, which can sometimes lead to dependency and decreased bowel function if overused.