After the Germans suppressed the 1944 Warsaw Uprising, they sent Rejewski's wife and children west, along with other Warsaw survivors; the family eventually found refuge with her parents in Bydgoszcz. Rejewski was discharged from the Polish Army in Britain on 15 November 1946. Six days later, he returned to Poland to be reunited with his wife and family. On his return, he was urged by his old Poznań University professor, Zdzisław Krygowski, to take a university mathematics post at Poznań or Szczecin, in western Poland. Rejewski could have looked forward to rapid advancement because of personnel shortages as a result of the war. However, he was still recovering from rheumatism, which he had contracted in the Spanish prisons. Soon after his return to Poland, in the summer of 1947, his 11-year-old son Andrzej died of polio after only five days' illness. After his son's death, Rejewski did not want to part, even briefly, with his wife and daughter, so they lived in Bydgoszcz with his in-laws. Rejewski took a position in Bydgoszcz as director of the sales department at a cable-manufacturing company, "Kabel Polski" (Polish Cable).