In two letters, one to Fr. Sterpi and the other to Bishop Albera, St. Luigi Orione wrote about his health, informing them of what had happened to him, his symptoms, how the doctor had diagnosed his diabetes, the treatment and other details. Besides all this, he joked because the doctor (a former student of his) would not allow him to drink wine for three days.
From the letter to Fr. Sterpi:
"I have felt absolutely exhausted for over a month, and I thought it was due to the pressure of my work; I couldn’t even write nor do any useful work. Then, as I was extremely thirsty, I began to wonder if there was something wrong, so when they tested my urine, they found I was diabetic. They wanted me to stay in bed for at least three days, drinking only water! Can you imagine it? If they had told me to stay in bed drinking only wine, maybe I could have accepted it, but drinking only water!!! and in bed, that’s asking too much!" 
From the letter to Msgr. Albera:
"I am quite well; I am slightly diabetic, but that is already better. They wanted me to stay in bed for at least three days, condemned to drink nothing but plain water. Can you imagine it?
And do you remember Gonella? He was one of our students at San Bernardino for his first year, and then he went on to St. Chiara. He is a doctor here now, a medical authority. (…) Do you know what I told him? “Listen to me, Gonnella, if you tell me to stay in bed for three days drinking only wine, such as "nebbiolo, barbera or grignolino", then I would be quite willing. I might then sing all day long, and it would be fine. But drinking only water, come on! show a little respect! Is this your gratitude to me for allowing you into our school?"