Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If you throw up involuntarily, then the fast is not broken, but if you were to induce vomiting deliberately, then the fast would be broken.
Responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
If you throw up involuntarily, then the fast is not broken, but if you were to induce vomiting deliberately, then the fast would be broken.
It is reported on the authority of Abu Hurayrah that the Prophet (peace be upon him), said, “Whoever throws up involuntarily need not make up for his fast (he may continue the fast), but if one induces the same, he must redo it (i.e., his fast is broken and he must therefore make up for it)” (At-Tirmidhi)
Almighty Allah knows best.