The World Federation One Stop Fiqh

Ruling 1619

If bits of food or other tiny items enter a fasting person’s throat and go down to an extent that it could not be called ‘eating’, it is not necessary for him to bring it out and his fast is valid. However, the items do go down to that extent [that it could be called ‘eating’], then he must bring them out even if this requires vomiting, unless vomiting is harmful or excessively difficult (mashaqqah) for him to the extent that it could not normally be endured. In the event that he does not vomit it but swallows it instead, his fast becomes invalid. Similarly, if he brings it out by vomiting, his fast becomes invalid.