Legend has it that as a boy, Trudo was playing, building a small church with some rocks. When a woman scornfully kicked over the rocks, she was struck by sudden blindness. Trudo cured her from this blindness after she asked for his forgiveness. He also allegedly was able to find spring water and cure other illnesses.

After Trudo's death, the abbey (the later Sint-Truiden Abbey) became the centre of a pilgrimage. This brought pilgrims and wealth to the neighbouring