Are there specific IRS rules requiring 501(c)(3) nonprofits to use their donations for the purpose intended by the donors and disallowing them from soliciting donations for one purpose and then using them for another? What recourse does a donor have for such a situation?
The IRS does not police the use of contributions. That is left up to the states under their charitable solicitation registration laws and/or general statutes against misrepresentation and misuse of funds. Unless a donor specifically retains the right to enforce conditions on a gift, it is often only the attorney general or local prosecuting attorney who has standing to challenge the misuse.