Does the return of fluid from anal enema through the vagina invalidate ablution?
Chapter on What Nullifies Purification
Al-Mughni
Book of Purification
Primary text
If one performs an enema (*ihtiqan*) in the anus, and parts exit through the vagina, ablution is invalidated. Similarly, if a man has intercourse with his wife not through the vagina, and his semen enters the vagina and then exits, ablution is invalidated for both parties, and they must perform Istinja (cleansing). This is because the exit is from the passage and is not devoid of moisture accompanying it from the vagina.
Supporting text
If they are certain that nothing exited, there are two possibilities: one is that invalidation occurs for both parties because an exit is the usual outcome, thus it invalidates like sleep. The other is that ablution is not invalidated because certainty of purity is not removed by doubt.