What change should a patient notify the health care provider about after a below-knee amputation?

After a below-knee amputation, the observation of a large amount of serosanguineous or bloody drainage is significant and warrants immediate attention from a health care provider. This type of drainage can indicate potential complications, such as bleeding, infection, or inadequate healing of the incision site. Monitoring the drainage from the surgical site is critical, as excessive bleeding can lead to serious health risks, including shock, and may require further medical intervention.

In contrast, reduced pain at the incision site is generally expected as healing progresses, and increased mobility of the limb can also indicate that the patient is adapting well to the surgical changes. An improvement in appetite reflects overall recovery and health but does not typically signal a concern that necessitates urgent communication with a healthcare professional. Thus, the presence of excessive drainage is the most critical change that should be reported.