Your bone marrow aspiration cytology is needed in view of weight loss.Complete blood count
also to see for heamtological diseases. Acute weight loss calls for through examination, and tests for searching the cause.
Your doc.wants colonoscopy
which may mean some pathology in bowels with , if you have developed malabsorption syndrome
, then too there can be excessive calcium and mineral loss in stools giving rise to osteomalacia
. for which serum calcium level should also be done. This also at times gives bone pains.