It is well-known that it is a Sunnah to hasten breaking the fast, and hence every fasting person should do so. If, while doing an operation, the doctor finds it extremely difficult to break his fast with fresh or dried dates, then he can break his fast with water. If he can’t do that then it is sufficient for him just to have the intention of breaking the fast until he finishes doing the operation.
Sheikh M. S. Al-Munajjid, a prominent Saudi Muslim lecturer and author, states the following:
First: The Sunnah is to hasten to break the fast as soon as the sun goes down. There are several Prophetic hadiths concerning that, such as the following:
Sahl ibn Sa`d quoted the Prophet (peace and blessings be upon him) as saying, “The people will continue to do well so long as they hasten to break the fast.”
Imam An-Nawawi said: “In this hadith we are urged to hasten to break the fast, after checking that the sun has indeed set. What this means is that the Ummah will continue to be in good shape and will be fine, so long as they adhere to this Sunnah. If they delay (breaking the fast) then this will be a sign of corruption that they have fallen into.”
Al-Muhallab said: “The reason behind that is to avoid making the day longer by taking from the night. It is also kinder to the fasting person and gives him more strength for worship. The scholars are agreed that this hadith refers to when it is confirmed that the sun has indeed set by visual sighting or by the testimony of two witnesses of good character – or of one such witness according to the more correct view.”
Second: The Sunnah is for the fasting person to break the fast with fresh dates; if he cannot find any, then with dried dates; if he cannot find any, then with water. If he cannot find any, then he should break the fast with whatever food and drink are available.
If the fasting person cannot find anything with which to break his fast, he should break his fast in intention, i.e., he should declare that his fast is over even if that is delayed, thus he will have hastened to break the fast and followed the Sunnah in that.
The late Saudi scholar sheikh Ibn `Uthaymeen said in Ash-Sharh Al-Mumti’ (6/269): “If the fasting person cannot find water or any other drink, or any food to break his fast, he should intend in his heart to break his fast, and that is sufficient.”
Based on the above, I can conclude that if this doctor cannot break his fast with fresh or dried dates, then he can break his fast with water. If he cannot do that because he is so busy doing the operation, then it is sufficient for him to have the intention of breaking the fast, and he can act in accordance with the Sunnah in this way.