Welcome to HCM,
I appreciate your inquisitiveness about the disease multiple myeloma
is cancer of plasma cells, constipation
is not the cause for it but usually it is detected by bone pain,high calcium level and Kidney failure and Anemia, ( CRAB).
Pan is severe and anemia causes weakness, appetite is reduced by disease and kidney failure.
Now it is diagnosed kindly take care about her treatment and diet. Chemotherapy
is given, and if suitable and cost is no bar stem cell transplantation
autologus may be possible there are good result with new therapy.. with correction of anemia if required Erythropoietin
Take care to prevent any fractures .
Wish her good Luck.