I’m very seldom sick, so being diagnosed with colorectal cancer and ultimately needing a total pelvic exenteration at age 48 took me by surprise.

I started having problems going to the bathroom in the fall of 2015. The constipation went on for two or three weeks, so I did the home remedy thing. But one day, I literally doubled over with stomach pain so bad that I had to leave work and go to an urgent care clinic.

The doctor...