One of my student’s doctor informed him that due to his diabetes and susceptibility to dehydration, as well as medications he is (and needs to be) on, the doctor is concerned about him going without drinking water for 24 hours. The doctor said he is at significant risk ( I spoke to the doctor and when I pushed him to be as specific as he could, he said maybe 15% chance) for kidney injury with long-term ramifications. The doctor said he should be drinking at least 3 cups of water over a 24 hour period, ideally more. While the doctor is very honest and very matter of fact, he personally is not very observant. I believe he gave his honest medical opinion, however he does not have the same instinct about fasting on Yom Kippur that a fully observant person does. Please advise. Thank you very much!
Diabetes and eating on Yom Kippur is tricky, as to how much he may have to drink or possibly eat, depending in the individual situation. I would advise your Rov to speak to the doctor directly to determine this.
Have Kesiva V’chasima Tova, and a year of Harbotzas Hatorah