Hello Janey and welcome to the site.
Dad had his operation this week so he/you will know by now that his bowel was left where it should be, so attached doesn't mean spread. I'm sure that if there had been any doubt about that his bowel would have been removed too.
As his cancer is the aggressive kind he will no doubt be facing further treatment. Keep us posted on what is offered to him and I'm sure somebody will be able to offer advice.
Don't despair. The fact that an operation was offered and done is, strangely enough, a good sign.
Be positive for your dad. Be positive for yourself. There are many men on here with living with aggressive (some even terminal) cancer and they have been for years.
We all think the worst case scenario when we hear that Cancer word. It's not always the case
Best wishes
Sandra