I suppose that there are people who over time return to eating as they did before .... but not a good plan as diet is directly related to colon health.
You need to look at foods said to be beneficial in combating cancer.
I have eliminated more from my diet than I have added.
I no longer eat any red meat products. No soda, no coffee, no high fructose corn syrup, avoid gluten, eggs, chocolate, baked goods, no fried foods and no deli meats or packaged meals for starters.
The idea is to protect your colon and gastrointestinal system from cancer recurrence as long as possible.
Forget food that is hard to digest. What you do eat, salads for instance, cut it up well to make digestion easier.
You have many questions to ask of doctors/ nutritionists perhaps but there is a wealth of information online with this subject.
I think for most, diarrhea and/or constipation after colon surgery can be expected. So that has to be taken seriously when planning what to eat.
It's just something else to think about and will become a major part of the healing process.
Prepare now for what is to come and all things later will be easier to deal with.
Best wishes to you always!!