SIBO Made Simple

Your Digestive System Cast of Characters (in Order of Appearance)

The GI tract is a series of organs joined in a long, winding path from the port of entry (your mouth) to the exit ramp (your anus). There are hollow organs that transport and process food—such as the stomach, small intestine, and large intestine, and solid organs—such as the liver, pancreas, and gallbladder—that don’t deal with food directly, but aid in breaking it down. Here’s a brief description of the main players and how they come together in this ensemble cast to keep your body fueled and healthy.

“Sorry, I Don’t Speak SIBO”: A List of Essential Terms

Reading about SIBO can sometimes make you feel as if you need to learn a new language. This section contains bare-bones definitions of some of the most referenced conditions, bodily functions, and processes in this book. If you ever find yourself confused or want to work on your SIBO literacy, flip back here.

GI, Interrupted: Getting to the Bottom of Your IBS Symptoms

Irritable bowel syndrome has long been thought of as a mystery, symptom-based disorder—what many physicians refer to as a “wastebasket diagnosis” that should only be reached after all other possibilities are ruled out and thrown in the trash.

Over forty conditions could cause the keystone symptoms of IBS: abdominal bloating, abdominal pain, constipation, diarrhea, or a combination. But more often than not, someone will walk into a doctor’s office with two or more of these issues, and with no further investigation they are diagnosed with IBS and sent on their not-so-merry, gassy way.

If this scenario sounds familiar, you are not alone.

IBS is the most pervasive gastrointestinal condition in the world, affecting anywhere from 10 to 20 percent of the global population, whereas GI diseases, such as celiac, make up only around 1 percent. IBS sufferers are twice as likely to be female, and therefore, that much more likely to be told that the distress is all in their head and the best medicine is a chill pill.

For this camp, learning about SIBO can be a welcome light at the end of the IBS tunnel. Before the twenty-first century, this type of overgrowth was only discussed in medical literature in isolated instances—usually when a section of the small intestine was removed. It wasn’t until the last decade that we’ve come to understand that SIBO is far more pervasive, and now estimated to be responsible for more than half of IBS cases.

Still, as awareness for SIBO grows, it risks becoming a similarly catch-all diagnosis, when in reality, it is really a symptom of a larger problem in your digestive tract, not a disease in and of itself. If you have SIBO, there’s always a reason the bacteria are overgrowing, and often several. It could be that endometriosis or a tumor is pressing down on your intestines. It could be inflammatory bowel disease—Crohn’s or colitis—which makes someone nine times more likely to develop SIBO. Similar to IBS, with SIBO, it’s not the what we should be after, but the why. Because a more serious problem can go ignored if we feel SIBO is the one answer we’ve been looking for after many years of suffering.

On the following cheat sheet, you’ll see the many disparate symptoms that might be a result of SIBO. As we get into the nuances of the different organisms that can colonize the small intestine (here), you may better understand why certain seemingly opposite symptoms (e.g., constipation or diarrhea, chronic weight loss, or stubborn weight gain) are present in some people and not others.

Women with SIBO will often report that they wake up feeling normal, but after breakfast, their abdomen balloons to the point of looking visibly pregnant. The timing, frequency, and location of your symptoms is one of the biggest indicators of whether you have an issue in your small intestine or another type of gut imbalance. Distension, that feeling of wearing an internal inner tube below your ribs, is one of the hallmark symptoms of SIBO. It’s a different sensation than what a woman might experience during her period. With SIBO, that bloating happens much higher, the pressure is harder, and it’s chronic.

Most SIBO sufferers will feel the impact of their meal within the first hour of eating, whereas GI symptoms six hours after your bean burrito are likely due to gas in the colon. If you find you’re experiencing pain or discomfort after every meal, that is more indicative of SIBO than are intermittent bouts of IBS, which may be due to an intolerance or exposure to a specific ingredient. The sample Symptom and Activity Tracker (here) should help you better identify where and when symptoms occur and whether food triggers could be at play.

In other words, just because you experience gas, bloating, diarrhea, or brain fog, it doesn’t mean you have SIBO—or, that it’s only SIBO.

The most important element of unpacking your symptoms is ruling out additional causes. SIBO is associated with many other disorders, and we are still in the process of understanding the chicken-or-the-egg relationship between them. Chapter 1 is all about helping you parse through your symptoms, test properly for SIBO, consider or rule out coinfections, uncover the malfunctions within your digestive system, and overall, discover a more complete picture so you can formulate the appropriate treatment plan in Chapter 2.

We’ll discuss the role that something as common as food poisoning can play in your intestines’ ongoing functionality (here) and why women may be more susceptible to foreign invaders than men are (here). Lastly, we’ll talk about the beast that is yeast and how Candida overgrowth can be an equally formidable foe for your small intestine (here).

SIBO SYMPTOM CHEAT SHEET

Playing Gut Detective: Uncovering Your Root Causes and Risk Factors

To be able to wrap your head around how bacteria can overgrow in the small intestine, you first need to understand your digestive system’s fundamental anatomy and functions.

We are constantly ingesting bacteria through our nose and mouth via the food we eat and our most basic interactions with the world around us. The labyrinth of our alimentary canal is designed to ward off the bad guys before they have a chance to join the bacterial ecosystem of our large intestine and potentially throw its delicate balance into disarray. To accomplish this, our digestive organs work together to produce a cocktail of naturally antibacterial substances. These include the industrious HCl in our stomach, bile from our gallbladder, and digestive enzymes from our pancreas. The latter two are secreted into the small intestine and act as safety nets, killing and arresting growth of whatever critters manage to get past the stomach.

The most robust safety measure, of course, is our own immune system. What doesn’t get killed by acid, bile, or enzymes must then face our immune cells, 70 percent of which live in our intestinal lining. When a foreign invader seems to be gaining ground, this battalion unleashes its own patented brand of antimicrobial toxins to fight it.

If all else fails and bacteria manage to survive these measures, your body can rely on its own anatomy to at least get rid of them in a timely manner. The migrating motor complex (MMC) is our small intestine’s local dishwasher, responsible for clearing the decks and street sweeping undigested food and unwanted critters through the canal after each meal. Because of this role, the MMC only kicks in during a fasting state of ninety minutes or more. If you have a noisy or gurgling gut in between meals, that’s a good sign that your MMC is not falling down on the job.