What Is SIBO and How is It Different Than IBS? Experts Explain

When you have abdominal pain, bloating, or discomfort, you may think that you have Irritable Bowel Syndrome (IBS) but you could actually have SIBO or Small Intestinal Bacterial Overgrowth. Yes, this is confusing, but it turns out there is a reason to figure it out since now there's a new less restrictive diet created by two doctors that can help bring much-needed relief to sufferers of SIBO. It's called the Low Fermentation Eating or LFE approach and it works as well as Low-FODMAP but you're allowed to eat many more foods that are nutritious so you can feel better, stay on the diet and be healthy too.

SIBO is a wildly misunderstood condition where bacteria that normally grow in other parts of the gut begin to grow in the small intestine. This growth triggers the bacteria to release gas or fermentation, as they ingest foods you eat, which causes pain, cramping, consti[pation or diarrhea, depending on the type of bacteria you are dealing with.

SIBO is a form of IBS, and while IBS is the most common cause of gastrointestinal distress, affecting millions of people, according to the Cedar Sinai gastroenterologists who have written The Microbiome Connection, Your Guide to IBS, SIBO and Low-Fermentation Eating, SIBO actually is an extremely common ailment that affects an estimated 11 percent of the world's population.

SIBO is a specific condition where bacteria from the colon back up into the small intestine, explains Dr. Ali Rezaie, half of the team that has written the book and created the Low-Fermentation Eating plan and co-founder of the Good LFE with Dr. Mark Pimentel. When these bacteria eat certain foods like sugar, they release gas, which has nowhere to go and causes inflammation, imbalance, and all sorts of unpleasantness associated with fermentation. But it happens more depending on your diet since these little buggers feed on sugar, dairy, meat, and carbs, and release gas such as methane, hydrogen, and hydrogen sulfide.

Your body doesn't have a way of getting rid of the gas the millions of bacteria produce as they eat – so it causes fermentation in the gut. That's when things go haywire, explains Dr. Ali Rezaie, MD, who is Medical Director of the Gastrointestinal (GI) Motility Program at Cedars-Sinai, Los Angeles, and has created a whole new plan for eating foods that will lower fermentation in the gut, along with his colleague, Dr. Mark Pimentel.

They dedicated their book to all those with a chronic invisible illness: "To those who suffer but don't look sick; to those who hurt but routine tests are inconclusive; to those who agonize in silence." If that sounds like you, and you are ready to try anything, including a new diet, then read on, since this may be part of your solution.

Together these two respected gastroenterologists have introduced a diet that is less restrictive than Low-FODMAP and allows for healthy food to be part of a long-term eating plan to cure SIBO and maintain gut health, called Low Fermentation Eating or "LFE.

Through microbiome research, these two gastroenterologists have come up with much-needed answers to the questions of what causes SIBO, how to diagnose it (you can do a non-invasive fasting breath test) how to eat to treat it, and what can help you get rid of it.

Dr, Rezaie explained to The Beet that they set out to offer an alternative dietary approach that will limit the fermentation caused by these bacterial organisms, which can number in the trillions, and that the Low-FODMAP diet that has been recommended to date leaves little room for living a healthy, satisfying life since it's so restrictive that people on it rarely can stay on it for long.

"It is no longer as simple as: Follow a low-FODMAP diet. That approach, where you have to restrict your foods to the point of being able to eat barely anything nutritious, was once a catch-all answer to people suffering from SIBO," Dr. Rezaie explains. It was a plan guaranteed to fail since even if you are able to stay on it for a while, as you add back nutritious fruits and vegetables, your symptoms return. Instead, they have devised a more lenient approach that allows for some fruits and vegetables, but in moderation, and by restricting certain foods you can tamp down on the fermentation in your gut, which means fewer symptoms, and more relief, while still allowing yourself healthy foods.

But first, he says, you need to answer the question, How do you know if you have SIBO? And what can you do about it once diagnosed?

"Gas, cramping, inflammation, lower abdominal pain, and any problems going to the bathroom – whether it's constipation, diarrhea, or general malaise," says Dr. Rezaie. "It depends which bacteria you have problems with," he says. "SIBO has a way of affecting different people differently. The one way to figure out what is causing you distress is to start cutting out likely culprits."

There is one non-invasive test, where after a night of fasting you do a breath test and by exhaling your doctor can measure the hydrogen sulfate and methane in your breath. Since you don't make those gases but bacteria do, it's a helpful way to figure out if you have SIBO. The other way is an invasive endoscopy but those are expensive and generally not necessary.

A diet that essentially starves these bad bacteria and pushes them back down to where they belong, in the colon, is the best way to treat SIBO, says Dr. Rezaie. That is not to say you should stay away from fermented foods such as pickles and kimchi. Quite the opposite, since those foods are not the culprits. The foods that bacteria feast on are the problem, which also are foods that are generally not great if eaten in large quantities, like sugar.

The exception is that you can have vegetables or beans, but keep your complex carbs to one serving per meal. So if you want to eat a large salad full of leafy greens, that will be healthy, so long as you don't add croutons, carrots, potatoes, and other starchy vegetables, which will become too many starches all at once, if the point is to lower the number of carbs you're feeding the overgrowing bacteria.

Carbohydrates. Aim to limit carbohydrates to 1 serving per meal. Avoid:

Vegetables. Avoid these vegetables or limit intake:

Dairy. While non-dairy alternatives are okay, avoid cow-milk dairy such as:

For years the Low-FODMAP diet was the only way to treat IBS or SIBO. Now two doctors have created a diet that is less restrictive and that can help bring relief to SIBO sufferers. Here's what to eat and what to avoid, and everything you need to know about SIBO.

For more expert advice, check out The Beet's Health & Nutrition articles.