The Girl Scouts are facing an official inquiry by the United States Conference of Catholic Bishops. At issue are concerns about program materials that some Catholics find offensive, and assertions that the Scouts associate with groups espousing stances in conflict with church teaching. The Scouts, who have parish-sponsored troops, deny many of the claims and defend their alliances. The inquiry will be conducted by the bishops’ Committee on Laity, Marriage, Family Life and Youth. It will look into the Scouts’ “possible problematic relationships” and “problematic” program materials, according to a letter from the committee chairman, Bishop Kevin Rhoades of Fort Wayne, Ind., to fellow bishops. Critics contend that Scouts’ materials should not contain links to groups like Doctors Without Borders, the Sierra Club and Oxfam because they support family planning or emergency contraception.