... oldest daughter who is now 21 had the same exhaust problem and both girls had CT scans and were told that they had swollen lympnodes in the abdomen area. My 21 year old was 18 at the time and read that singular can cause this and stopped taking it at the age of 19.5 to see if the pain stopped so far she has not had another eposide but its weird that a pill could cause such severe pain that required both of them to be treated with morphine