U.S. officials have approved the first pharmaceutical-grade version of the so-called fecal transplant procedures that doctors have increasingly used against hard-to-treat intestinal infections.

The Food and Drug Administration on Wednesday approved Rebyota for adults who have trouble fighting off infections with Clostridium difficile, commonly referred to as C. diff, a bacteria that causes nausea, cramping and diarrhea. The infection is particularly dangerous when it reoccurs and is linked to about 15,000 to 30,000 deaths a year.

For more than a decade, some U.S. doctors have used stool samples from healthy donors to treat the condition. The healthy bacteria from donors’ gut has been shown to help recipients fight off C. diff bacteria. The procedure has grown more common as many patients no longer respond to traditional antibiotics.

But the proliferation of stool banks and fecal transplant practitioners across the country has created regulatory headaches for the FDA, which doesn’t traditionally regulate doctors’ medical procedures. The FDA has rarely intervened, provided stool donors are carefully screened for potential infectious diseases.

The new therapy from Ferring Pharmaceuticals Inc. is manufactured at a facility in Minnesota from stool donations that are screened for dozens of infections and viruses. The therapy is delivered via the rectum by health professionals as a one-time procedure.

The FDA said it approved the treatment based on results from two studies in which 70% of patients taking Rebyota saw their symptoms resolve after eight weeks, compared with 58% of patients getting a placebo.

The new treatment is only for patients who have already taken a course of antibiotics for recurrent infection. The condition is more common in seniors and people with weakened immune systems.

(AP)