Answer:
Unilateral radicular pain symptoms that extend below the knee and are equal to or greater than the back pain.
Explanation:
The medical term diagnosis of exclusion refers to a disease or medical condition whose presence cannot be confirmed with complete certainty only by examination or testing. The GP explained to Sam that low back pain is a diagnosis of exclusion, so more testing and more information would be needed to try to find out what medical condition Sam has.
Regarding Sam's lower back pain, the symptoms that would alert the clinician to the more serious discovery of a pulpous nucleus or herniated disc would be unilateral root pain that extends below the knee and is equal to or greater than back pain.