My mom is having half of her colon removed in the morning and her dr. would also like to prevent ovarian cancer by removing her ovaries. is that good?

Probably unnecessary: Unless there is a genetic syndrome, there would be no role for this. Maybe it would be appropriate to do a ct scan of the abdomen and pelvis first. However, i would not recommend the ovaries to be removed. Hope this helps.

Risks v. Benefits: The ovaries are a "preferred" site for the spread of some colon cancers; therefore, in a postmenopausal woman, some surgeons believe that the benefit of "prophylactic" oophorectomy outweighs the risk. If your mother or you are uncomfortable with this recommendation, please clarify with her surgeon.

Not likely.: This was a common practice in the past. There is no strong evidence to support this practice outside of special circumstances, i.e. Genetic issues.