Can c diff go away on its own?

Rarely: Yes, but not often. Most of the time c. Diff needs to be treated with an antibiotic (there are a few) before it improves.

Yes, but: if you have symptoms, it is better that it be treated with antibiotics and/or fecal transplant. Just having C diff is not an issue, unless you have diarrhea. About 3% of the people carry C diff without any issues and do not need treatment. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs.