My son was diagnosed with mesenteric lymphadenitis 8 weeks ago. this along with back pain has not seemed to resolve. how long do you wait it out?

A week...: Mesenteric lymphadenitis usually clears up in 7-10 days without a problem so still having symptoms at 8 weeks should bring up questions about other things going on.

May last 8 weeks: Symptoms of mesenteric adenitis can be vague and frustrating, and can last for several weeks. Ct findings might be confirmatory, but may also be non-specific. It depends on the degree of pain and other symptoms as to whether he needs further workup. But I have to say, back pain is not a typical finding, so he may indeed need further evaluation.