lpas - I don't think you need to be unduly concerned about possible bowel blockages. Based on my husband's experience, there were no concerns at all post-surgical recovery. He did suffer from constipation but ultimately figured out a diet and methods to overcome it. And, by the way, my DH was hospitalized 7.5 weeks following his resection due to multiple complications, so if anyone would have developed a blockage then, I'm sure my DH would have!
I think that blockages become an issue at end-stage for some colon cancer patients, particularly if there is abdominal/peritoneal involvement. The tumors and caking that form then can cause blockages by the cancer burden pressing into the small and/or large intestines. My DH did experience this several times in his last few months, but the blockages always resolved themselves with a wait-and-see, NPO treatment while hospitalized. I may not be representing this correctly, but I believe this is the case. However, as we all know, I am not a doctor.
Frankly, I was amazed at what my DH was able to eat post-surgical recovery. His doctor told him to eat whatever he fancied, and he did.