How will having colon radiation affect my long-term health?

Varies. Depends on the side effects you experience. It may be very bothersome later on if radiation colitis (colon) or proctitis (rectum) develops, which can be very irritating and annoying with its attendant diarrhea. Fortunately, the vast majority of patients have little if any long lasting side effects.
Unlikely to affect. Radiation to the colon typically will not affect long-term health. On rare occasions there can be chronic changes in bowel habits such as diarrhea, or scar tissue can form which has the potential to cause a mechanical obstruction.

Related Questions

Are there long-term effects of colon radiation on my child's health?

I'm puzzled.. Is your child receiving abdominal radiotherapy, perhaps for neuroblastom or wilm's tumor? Or, are you receiving external beam and wonder if it affects your child? If the former, there can be small intestine problems, but unlikely at dose used. If it is your radiotherapy, you expose your child to no hazzard, and you do not bring any radiactivity out of the facility with you. Read more...
NOT CLEAR. Question not clear, why received colon radiation? And are u asking if you get pregnant after receiving radiation? Please elaborate. Read more...