What is the ruling on the fast of a woman who underwent gastric bypass surgery, which requires her to eat every three hours, knowing that the fasting period in her country of residence (Belgium) reaches 21 continuous hours?

If you are harmed by fasting or fear that your illness, from which recovery is hoped, will worsen, you are permitted to break your fast, and you must make up the missed days, as Allah Almighty says: "And whoever is ill or on a journey - then an equal number of other days." However, if the hardship is ordinary, then breaking the fast is not permissible.