Why does Eliezer have to have an operation on his leg?

The correct answer highlights that Eliezer undergoes an operation on his leg due to swelling. This swelling is likely a result of the harsh conditions and the physical toll of his experiences during the Holocaust. Throughout his journey, he suffers from inadequate medical care, malnutrition, and the stress of the environments he finds himself in, which can easily lead to physical ailments such as swelling. This condition requires surgical intervention as it signifies a significant problem that could lead to further complications if not addressed.

The focus on swelling as the reason for his operation emphasizes the broader themes of suffering and the neglect of the prisoners' health in the concentration camps, illustrating the dire conditions they faced. Understanding this context provides insight into Eliezer's deteriorating physical state and reflects the general experiences of many individuals during that period.