Rules Regarding Things, which Invalidate a Fast
1662. If a person intentionally and voluntarily commits an act, which invalidates fast, his fast becomes void, but if he does not commit such an act intentionally, there is no objection in it. However, if a person in Janabat sleeps and the details which are mentioned in the rule no. 1640, does not do Ghusl till the Adhan for Fajr prayers, his fast will become void.
1663. If a fasting person forgetfully commits an act which invalidates fast and thinking that since his fast has become void, intentionally commits another act which invalidates fast, his fast will become void.
1664. If something is inserted forcibly down the throat of a fasting person, or his head is forcefully immersed inside the water, his fast does not become void. However, if he is compelled to break his fast by intimidation, like, someone warns him, if you will not eat the food, your life or wealth would be at stake, and he breaks the fast to ward off the danger, his fast will be void.
1665. A fasting person should not go to a place where he knows that something will be inserted in his throat or that he will be compelled to break his fast by his own hands. Moreover, if he goes there and something is inserted into his throat or he is compelled to commit an act by his own hands, which invalidates a fast, his fast will become void. However, if he makes an intention to go there although he does not go, his fast will become void.