"C. diff "infection can be treated with some antibiotic medicines. However, "C. diff" is an antibiotic-resistant bacteria. This means that many antibiotic medicines cannot kill "C. diff". This can make "C. diff" infection very difficult to treat. Many people with "C. diff" infection have relapses (they get better for a while, but then get sick again). This happens to about one in every five people with "C. diff" infection. 