Is it permissible for a fasting person to chew chewing gum (al-'ilk)?
General Chapter
Al-Mughni
Book of Fasting
Primary text
Chewing gum is divided into two types. The first type is that which has parts that disintegrate (the poor quality gum). Chewing this type is impermissible unless the person ensures none of the saliva containing the disintegrated parts reaches the throat. If any part reaches the throat, it invalidates the fast, similar to intentional eating. The second type is the strong gum that hardens upon chewing. Chewing this type is disliked (makruh) but not forbidden (haram). Those who disliked its chewing include Al-Sha'bi, Al-Nakha'i, Muhammad ibn Ali, Qatadah, Al-Shafi'i, and the companions of Al-Ra'y (Hanafi school), because it causes the mouth to secrete saliva, gathers saliva, and causes thirst.
Supporting text
Aisha and 'Ata' permitted chewing it because it does not reach the interior of the body, comparing it to placing a small stone in the mouth. If one chews it and does not find its taste in the throat, the fast is not broken. If the taste is found in the throat, there are two opinions: one states it breaks the fast, similar to kohl (eyeliner) if its taste is found in the throat. The second opinion states it does not break the fast because nothing physically descended, and mere taste does not invalidate the fast, citing the example of tasting colocynth (hanzal) applied to the sole of the foot without invalidation, unlike kohl whose particles reach the throat.