What are the fast-invalidating acts and the types of things that break the fast, and what are the things that do not break the fast?

Things that break the fast are of two types: those that cause depletion, such as intentional vomiting, menstruation, and cupping; and those that cause repletion, such as eating and drinking. The Quran has gathered the principles of things that break the fast in the Almighty's saying: ﴿So now, have sexual relations with them and eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the night.﴾

The things that invalidate the fast are seven: 1. Sexual Intercourse: This is the greatest sin among the things that break the fast and necessitates repentance, completing the day [in abstinence], making up for the fast (qada'), and a severe expiation (kaffarah mughalladhah). 2. Masturbation: Intentionally ejaculating semen, which necessitates repentance, abstaining for the rest of the day, and making up for the fast. 3. Eating and Drinking: Introducing food or drink into the stomach, whether through the mouth or the nose. 4. What is equivalent to eating and drinking: Such as blood transfusions, nourishing injections that substitute food and drink, and kidney dialysis. 5. Drawing blood through cupping and similar methods: Such as blood donation that causes depletion. 6. Intentional Vomiting: Whoever intentionally vomits must make up for the fast. 7. Onset of Menstruation and Postnatal Bleeding (Nifas): Whenever a woman experiences either of these, her fast is invalidated.

These things that break the fast — with the exception of menstruation and postnatal bleeding — invalidate it only under three conditions: that the doer is knowledgeable and not ignorant, mindful and not forgetful, and acting of their own free will and not under duress.

Things that do not break the fast include: enemas, eye and ear drops, tooth extraction, treating wounds, angina tablets placed under the tongue (provided swallowing is avoided), what enters the vagina or urethra for therapeutic purposes, drilling and cleaning teeth, rinsing the mouth and gargling, and localized mouth spray (provided swallowing is avoided), oxygen gas and anesthesia (unless administered with nourishing liquids), what is absorbed into the body through the skin, inserting a catheter into arteries, abdominal and stomach endoscopies (without liquids), taking biopsies (without solutions), and the insertion of therapeutic instruments into the brain or spinal cord.