Like any other ailment, it varies. I had a friend that had pancreatitis and it was a months long process which even involved a feeding tube. However, the good news is that this occurred about 5-7 years ago. I am sure progress has been made in that time and in the proper procedures for treatment. Recently, I had a lady friend that was in the hospital only about 10 days and she was quite elderly on top of the pancreatitis issue. So, I think your general over-all health would have a barring also. It's a painful disease as you no doubt know. I wish you (or the person with the disease) well.
