Researchers are examining two drugs used to treat other ailments to see if they’re effective for people with irritable bowel disorder.

For people with inflammatory bowel disease (IBD), the next breakthroughs in treatment may already be on the way.

This month at the United States’ first annual Crohn’s & Colitis Congress, researchers and clinicians are looking ahead at what those breakthroughs could be.

IBD is an umbrella term for a variety of symptoms and conditions that includes Crohn’s disease and ulcerative colitis.

Both diseases occur due to an abnormal response by the body’s immune system, causing chronic inflammation to the bowel and gastrointestinal (GI) tract.

Roughly 3 million U.S. adults have the disease. Experts estimate that number may be closer to 5 million worldwide.

IBD is more common in developed countries, although it’s not clear why.

Expert’s opinions differ on this issue because IBD is caused by both genetic and environmental factors.

There’s no cure for IBD. It’s commonly treated with anti-inflammatory medication.

However, even the best current treatments, drugs known as anti-TNF or TNF inhibitors, can yield lackluster results.

“They work in patients initially about 60 percent of the time… Over the following year, of the 60 percent that are responsive, as much as 30 to 50 percent may lose responsiveness,” said Dr. Brent Polk, professor of pediatrics and gastroenterology at the University of Southern California (USC) and chairman of the Congress.

“So, by a year they may only be effective in 30 to 40 percent of patients. As you can see there is a huge gap in our currently best available treatment,” Polk told Healthline.

In the quest for better IBD drugs, researchers have turned their attention to two existing medications that are currently approved for other diseases.

Rifaximin is one of those. It’s currently available in the United States to treat a handful of conditions, including irritable bowel syndrome and traveler’s diarrhea.

According to new research presented at the Congress, rifaximin may be an effective treatment for Crohn’s disease as well.

“In humans, antibiotic approaches to Crohn’s or ulcerative colitis had really limited response and so one of the exciting things about this rifaximin study was that it begins to address that we might need to go back and look at a subset of patients for specific antibiotic approaches,” said Polk.

The microbiome of the gut — that is, all the bacteria and microorganisms that live in the GI tract — plays a role in the development of IBD. Previous attempts to treat IBD with antibiotics have shown limited effectiveness.

According to the rifaximin study authors, “These results offer renewed hope for the use of antibiotics in treating Crohn’s disease.”

Researchers also touted tofacitinib, a class of drug known as a Janus kinase inhibitor, as a potential new pharmaceutical for both Crohn’s disease and ulcerative colitis.

Tofacitinib is already on the market in the United States for the treatment of rheumatoid arthritis under the trade name Xeljanz.

“The drug has shown excellent effect in ulcerative colitis patients,” said Polk.

However, he explained that part of the problem with IBD isn’t just finding a new drug that works, but finding out which patients it will work for.

With IBD there isn’t a one-size-fits-all solution to treatment.

“We are currently limited in our ability to predict which patients will respond to which therapies,” said one expert last year.

Gastroenterologists are eagerly looking for some kind of test, such as a sample of gut microbiome, that could predict how an individual person with IBD might react to a particular kind of treatment.

Nonetheless, Polk and his colleagues at the Congress are optimistic about the new drugs and treatment options that will become available in the near future.

“We are very excited to see the new drugs that are being tested now and hopefully will be available to patients three to five years from now,” he said.

“As we begin to match up patients with their response to these new medications, hopefully we’ll be getting a better idea of which medicine goes best with which patient, based on the causes of their IBD or potentially some biomarker,” Polk added.