For the 20 percent of Americans who need secondary gastric bypass surgery, there is a new, less painful technique available.

Marcia Mcalla, 36, thought she was on her way to having the body she always wanted when she underwent Roux-en-Y gastric bypass surgery in 2002. At the time, she weighed 300 pounds and had tried every fad diet.

"I tried the grapefruit diet, the cabbage soup diet, Weight Watchers and Jenny Craig,” Mcalla told FOXNews.com. “I just never really was successful at keeping it off."

Gastric bypass helped her lose about 150 pounds, but there were complications, including nausea and indigestion, said the New Jersey social worker.

So when Mcalla found out she needed a second gastric bypass, she was relieved to find out doctors were going to use a new technique called StomaphyX.

The non-invasive procedure was much different from her first surgery, which involved a large incision and made her tired for about six months.

"Even though its surgery, it's all through the mouth," Dr. Muhammad Feteiha, director of minimally invasive surgery at Overlook Hospital in Summit, N.J., told FOXNews.com. "So when Marcia wakes up, she won't have any incisions, she'll have very minimal pain, and she'll be able to go home."

Click here to watch a video on StomaphyX.

Other benefits include:

— Less risk of infection

— Shorter surgery time (it takes about 45 minutes)

— Patients can return to work in as little as one day

If Mcalla were to have traditional gastric bypass surgery again, it would involve reopening her incision, removing part of the pouch and small intestine, and then reattaching it, Feteiha added.

And, she would have to stay in the hospital for seven to 10 days.

Only about 150 doctors are using the StomaphyX technique around the country. It was approved in March 2007 by the U.S. Food and Drug Administration.

To date, about 500 patients have undergone the surgery, which allows doctors to re-shrink the stomach without even using a scalpel.

Research is being done to see if StomaphyX can become a primary surgery in the future, Feteiha said.