Most people have heard of irritable bowel syndrome (IBS), a common disorder that affects the stomach and intestines, causing diarrhea, constipationand bloating. But now, a similar condition known as SIBO is getting more attention.

Recently, Selena Gomez shared that she is battling SIBO, after body shaming criticized the “Only Murders in the Building” actress for posing with her hand in front of her torso for the premiere of her new film “Emilia Pérez”, implying that she was trying to hide her body. No one should ever defend himself or his body, but according elleGomez responded in a since-deleted comment on TikTok, explaining, “This makes me sick. I have (SIBO) in my small intestine. It lights up. I don’t care that I don’t look like a stick. I don’t have that body. No, I’m just a victim.

SIBO is actually one of the most common digestive disorders, often associated with other pre-existing conditions such as Crohn’s disease or celiac disease. The symptoms aren’t limited to bloating, though. The condition can also cause diarrhea, nausea, indigestion and discomfort while eating. To help reveal everything you need to know about SIBO, we turned to a doctor. Next, a doctor explains SIBO symptoms, causes, and potential treatment.

Experts featured in this article:

Laura PurdyMD, is a family medicine physician and founder of telehealth company Swell Medical.

What is SIBO?

“Small intestinal bacterial overgrowth, commonly referred to as SIBO, is a condition that results from an overgrowth of bacteria in the small intestine and gut,” says Laura Purdy, MD, family medicine physician and founder of telehealth company Swell Medical . It’s normal and healthy to have some bacteria living in your gut, but too many can wreak havoc in your intestines and cause problems with digestion, ultimately leading to uncomfortable symptoms, she explains.

To break it down a bit more, bacteria in the small intestine digest carbohydrates and turn them into gas and short-chain fatty acids (fatty acids with fewer than six carbon atoms that are a byproduct of bacterial fermentation in the gut), according to the Cleveland Clinic. More bacteria can mean more gas and other byproducts, making you feel gassy.

Excess bacteria also feed on protein and vitamin b12, according to the Clinic, which can worsen fat digestion and lead to poor absorption of nutrients and fat-soluble vitamins. The result? Unpleasant gastrointestinal symptoms.

Symptoms of SIBO

SIBO is usually marked by the following signs and symptoms, according to Dr. Purdy. You may have some or many of these symptoms, depending on the severity of your condition.

If left untreated, SIBO can also cause poor fat absorption, on Yale Medicinewhich can lead to vitamin D, vitamin B12 and iron deficiencies as the excess bacteria eats up all the nutrients.

What causes SIBO?

SIBO occurs when there is an overgrowth of bacteria in the small intestine and large intestine, says Dr. Purdy. Your body normally maintains the balance of flora in your gut through a complex network of chemical and bodily functions, according to the Cleveland Clinic, but when one or more of these functions are dysfunctional, SIBO can occur.

Like most conditions, it’s difficult to narrow down the exact culprit of SIBO, but here are some common causes.

How is SIBO diagnosed?

The most common and noninvasive way to diagnose SIBO is with a breath test, Dr. Purdy explains. “This test is done after consuming a sugary solution (a mixture usually made of glucose and water) and measures the level of hydrogen and/or methane in the breath,” she says. If you exhale and there is a rapid increase in hydrogen and/or methane levels, it may be an indication that there is an overgrowth of bacteria in the small intestine.

A culture of fluid from the small intestine can also identify bacterial overgrowth, although it’s more invasive, Dr. Purdy says. To get fluid samplea healthcare provider will pass a long, flexible tube down your throat and through your upper digestive tract to your small intestine. From there, a sample of intestinal fluid is drawn and tested in a lab to identify bacterial growth.

In addition, your doctor may order a blood test to identify vitamin deficiencies or a stool sample to determine if there is excess undigested fat or bile acids. An X-ray, CT scan, or MRI may also be needed to evaluate organ function and potential structural problems.

How is SIBO treated?

It may sound counterintuitive, but SIBO is typically treated with a course of antibiotics to help reduce bacterial growth, Dr. Purdy says. Keep in mind that antibiotics can wipe out good and bad bacteria in your gut, so it’s essential to follow your doctor’s instructions to prevent bacterial resistance, she adds.

If SIBO has caused nutritional deficiencies, a healthcare provider may prescribe oral supplements or intramuscular injections to help fill the nutritional gap, especially if you are deficient in vitamin B12, according to the Mayo Clinic. However, you should always get your doctor’s approval before starting any new supplement, as they are not FDA approved and therefore always carry some risk.

Finally, SIBO can sometimes be managed by a the low-FODMAP diet (a diet plan that cuts out certain types of carbohydrates that are usually hard to digest) because some carbohydrates feed bacteria in the gut and can make uncomfortable symptoms worse, says Dr. Purdy. Again, you should always contact your doctor to discuss a treatment plan before making any major changes to your diet.

That said, if you have an underlying condition that predisposes you to SIBO, it’s essential to talk to a doctor to address and treat the root cause.

Andi Breitowich is a Chicago-based freelance writer and graduate of Emory University and Northwestern University’s Medill School of Journalism. Her work has appeared in PS, Women’s Health, Cosmopolitan and elsewhere.