There were no guidelines for fecal transplants. Then, a patient died.

In June, after a patient died and another was sickened from a fecal transplant that contained drug-resistant bacteria, the Food and Drug Administration stepped in and set new guidelines for the procedure.

The guidelines specified that both donors and their stool should be screened for the presence of “multidrug-resistant organisms.” They were included in an alert issued by the agency stating that the two patients who got sick had weakened immune systems, and that the donor stool they received had not been tested for the specific superbug that made them ill.

But no additional information on the cases was provided, such as how the stool was processed, how it was given to the patients or what it was being used to treat.

The announcement raised more questions than it answered. Chief among them: What happened, exactly, in the two cases? And, given the increasing threat posed by drug-resistant bacteria, why weren’t these guidelines already in place?