For patients with nearly no options to treat a persistent bacterial infection wreaking havoc on their bowels, a transplant of someone else's fecal matter, delivered by enema, helps heal in nine out of 10 cases, according to a new study.

"It's unbelievably effective," said Dr. Neil Stollman, who was not involved in this research, but who has reported similar success using colonoscopy to deliver a stool transplant.

The procedure is used primarily to treat patients with infections from the bacterium Clostridium difficile (see Reuters story of January 19, 2011).

Typically, the bugs colonize the gut after antibiotics used to treat other infections have disrupted the body's normal bacterial harmony.

"C. diff," as doctors refer to it, can cause chronic diarrhea, weight loss, abdominal pain and complications such as kidney failure or a hole in the colon.

Most people recover from the infection, often with another course of antibiotics.

But a minority have recurrent cases of infection, or never respond to treatment.

The idea behind fecal transplant from someone with a healthy gut is to restore bacterial balance to the patient's intestines.

In the study, led by Dr. Christine Lee at McMaster University in Hamilton, Ontario, the researchers asked two healthy volunteers to donate fecal matter, which was diluted in water and given to 27 patients who had failed to recover after antibiotic treatments.

Unlike earlier studies that have used a colonoscope or a tube through the nose into the stomach, Lee's group used an enema to inject the feces.

"The rationale for using an enema is it can be used in any setting and it's not an invasive procedure," Lee told Reuters Health.

All but two of the patients recovered after the procedure, and the vast majority felt better within one day, Lee and her colleagues report in Archives of Internal Medicine.

"I would recommend it to anyone who has had recurrent Clostridium difficile infection. Right now we're dealing with a high rate of relapse, particularly in light of the type of strain that's circulating now. It's difficult to treat," Lee told Reuters Health.

Stollman, who practices at Northern California Gastroenterology Consultants, said only about 10 percent of patients have the nasty C. diff infections that might make them good candidates for the stool transplant, but that number is on the rise.

"C. diff is exploding," Stollman said.

Lee's team notes that C. diff infections tripled between 1996 and 2005, now affecting about 84 out of every 100,000 people.

Stollman said that so far he has seen no drawbacks to the procedure, but given that most studies are only several years old, it's unclear whether long term side effects could emerge in the future.

How, exactly, the transplanted material helps is unknown.

Lee said it could be that the newly introduced bacteria outcompete the C. diff bugs, or it could be that bacterial by-products in the stool help restore balance to the gut.

"The whole underpinning of this procedure is, if I don't know which bacteria to put in and in what concentration, let's put it all in," said Stollman. "It's an inelegant procedure with an elegant outcome."