My old man was diagnosed in the early 80's and had 5 resections before he died in 2015. As you said advancements in surgery have come a long way. My dads last surgery was to remove the infected section of intestine, turn it inside out and re-stitch it back in. His body fluids then effectively washed the infection off of the previously infected bit. Before that it was a case of treating it with steroids until it became so infected, a section was removed, until a colostomy bag was the final outcome.
I guess living in and around it, I never noticed if the old man became more irritable. I know at times he was doubled up in pain, but he just kind of got on with it. I guess anyone who has to take steroids long term is subject to mood swings.
