Praise be to Allah.
Concerning enemas which are given to sick people to counteract constipation, there is a difference of opinion among the scholars. Some say that enemas do break the fast, based on the fact that everything that reaches inside the digestive tract breaks the fast. And some of them said that enemas do not break the fast. Among those who said that was Shaykh al-Islam Ibn Taymiyah, who said that this is not food or drink, and it is not like food or drink.
What I think is that we should look at the doctors’ opinions concerning that. If they say that the enema is like food or drink, then it should be classified as such and thus it breaks the fast. If they say that the enema does not give the body what food and drink give it, then it does not break the fast.
For more, please see these answers: 38023 , 8652 , 37749 and 95062 .
And Allah knows best.