Final answer:
Intussusception is the condition that causes bowel obstruction when one section of the intestine telescopes over another, most commonly in children.
Step-by-step explanation:
The condition that causes bowel obstruction when one section of the intestine telescopes over another and is most common in children is called intussusception. Intussusception occurs when one segment of the intestine slides inside another, causing a blockage. This condition can be serious and may require immediate medical intervention.