Should I Take My Teenage Son, With A History Of Heart Defects, To The GP For A 4-day Stomach Ache?

My 15 year old son has been complaining of a stomach ache for a few days (4) He drinks a lot of lucozade and prefers to be awake at night than day. He also has a congenital heart defect avsd repaired and mv repair waiting for the next big leak. Should I take him to the gp.