Hi Ari!
Welcome! I wish you lots of good luck on your upcoming surgery!!
I had resection surgery in 97. I had three intestine-intestine fistulas and one broke off causing a huge abcess. My surgeon said that I could possible wake up with an ostomy bag, or that they would be able to do a resection. I woke up with no bag, so I'm not sure how long one would need to stay in place. I think most times it might be about a month, but it depends a lot on how you are healing. I didn't have any problems with septicemia or other infections after. And actually had about 6 wonderful years of remission after the surgery.
I know in my case surgery was the last resort. They tried medications for the abcess, but they didn't work and the doctors were worried about infection. Has your doctor or surgeon discussed other options for you other than surgery? I always feel like surgery should be the very last resort, but you also don't want to take the chance that things get worse.
If you do end up having surgery - make sure to ask your doctors about any extra vitamins you might need. My resection was at the terminal ileum and as a result I can't really absorb B12 well from food or oral vitamins and have to do a shot at least once a month. No one ever told me this until 6 years after the surgery and I was dangerously low on B12.
Wishing you good health and a safe surgery!!