What is the ruling about a person who cannot maintain ablution due to colectomy?
Things like blood, purulence, urine, feces, and suppuration which come from the place of excuse and get on the underwear of the excused person do not prevent him/her from establishing prayer as long as the condition of being excused continues. Because it is not possible to avoid this situation for the condition of being excused continues (Ibn Abidin, Radd al-Muhtar, I, 506-507).
A person, who underwent colectomy, defecates constantly or defecates throughout a prayer time without cease and repeats it at least once within each prayer time is considered as an excused person. Such people perform their prayers by performing ablution for each prayer time separately according to the Hanafi school. They may establish as many nafl or fardh prayers as they want with this ablution within the same prayer time (Marghinani, al-Hidayah, I, 219)
According to the Maliki school, the ablution of an excused person is not nullified by the beginning or end of the prayer time but by the things that invalidate ablution other than the excuse (Ibn Rushd, Bidayah, I, 35; Dasuqi, Hashiyah, I, 114-118).
In the event that the excuse of a person causes an extreme hardship to him and he has serious difficulties while performing ablution, he may act by this view of the Maliki school.
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS