A huge number of Americans suffer from IBS symptoms, and this number is increasing.
My job as a Functional Medicine doctor is to help patients figure out what is wrong and how to fix it. I spend a lot of time helping people with digestive symptoms, and over the years I’ve uncovered a lot of the different reasons why people struggle with bloating, gas, abdominal pain.
I hope this article helps you understand some of the common causes for IBS so that you can finally start to feel better!
SIBO
If you’re reading this you might have already heard of SIBO, which stands for Small Intestinal Bacterial Overgrowth. The basic concept is that you’re supposed to have a large number of bacteria in your large intestine, but not your small intestines. This is because bile and stomach acid (both of which kill bacteria) empty into the first part of your small intestine, and work to clean these sections of problematic microbes. When things are working normally, you should begin seeing bacteria increase only at the end of the small intestines as you approach the Ileo-cecal valve which marks the end of the small intestine and the start of the large intestine.
From this description you can probably guess one of the most common causes of SIBO - when a patient is put on a medicine like omeprazole or pantoprazole (Proton Pump Inhibitors) that strongly disrupt stomach acid production. It’s worth noting that these medicines are FDA approved for short courses, up to 12 weeks, yet most doctors don’t think twice about prescribing these for decades.
Another common scenario is the disruption to the microbiome that can occur after antibiotic treatment, or following a stomach bug.
I have also seen this occur as a result of a sliding hiatal hernia (learn more below), when the stomach acid production drops with age or from autoimmunity, and sometimes simply due to a good old fashioned bad diet. (When I was first learning Functional Medicine I thought it would be a good idea to drink a LOT of heavy cream in order to learn more about a ketogenic diet. I ended up with a nasty case of SIBO after months of feeding my bacteria all those delicious milk sugars…)
Happily, SIBO is relatively straightforward to treat and most of my patients are feeling significantly better within weeks. If you’ve been struggling with gas, bloating, diarrhea, constipation and reacting to seemingly everything - don’t worry! There are lots of tools (LINK) that we can discuss to help you feel better.
Diet
Processed Food
Despite exercising more than our European friends, while eating less and less sugar the American public continues to suffer with staggering amounts of obesity. This is because over the last several decades, the American Diet has become more and more processed. Emerging scientific evidence strongly points to the degree of processed food being the number one risk factor in a host of metabolic conditions.
There is a spectrum of processed foods moving from minimally processed foods like cheese, milk, and deli meats that are really not a problem, all the way up to Ultra Processed Foods such as breakfast cereal, twinkies, microwave meals and fast foods. Where people really get into trouble is when the Ultra Processed Foods begin to make up a large percentage of their caloric intake. Very large corporations have spent a lot of time and money designing highly addictive food products that can stay shelf stable for a very long time at the lowest price possible. Don’t be fooled by a label claiming “heart healthy and gluten free” - these companies are interested in your money, not your health
To understand this topic in more detail, I highly recommend the book Ultra-Processed People, by Chris van Tulleken. He describes a processed food as anything with one or more ingredients that you don’t have in your kitchen plus it comes wrapped in plastic. Read the book to find out what happens when he eats a diet of 80% processed food for a month.
Working on lowering processed food consumption is a common starting point for many of my patients because I have found that as patients replace processed foods with whole foods they become more resilient, less symptomatic,and heal quicker, regardless if they are on a mediterranean, keto, vegetarian or paleo diet.
Fibers & FODMAPs
Remember the “colonoscopy, fiber, antidepressant” approach favored by too many GI doctors? The simple fact is that most patients with IBS feel bloated, crampy and feel awful when they are given fiber supplements or are placed on higher fiber diets. This is generally due to a problem with the number or type of bacteria in their small intestines, and giving fiber to these patients is like pouring fertilizer on a garden overgrown with weeds.
Generally speaking, I find patients with GI symptoms generally feel the best by starting on a lower fiber diet. As they heal and their gut becomes healthier we are able to add more and more fiber to get them the broadest diet possible.
This is why I recommend the low FODMAP diet so often to my patients. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols, which are types of sugars that are naturally found in certain fruits, vegetables, dairy and wheat products. The trick is that while these sugars are difficult for you to absorb, they are the perfect food for microbes in your gut. By going on a low FODMAP diet, you lower the types of fiber most likely to bother your gut and cause you to have symptoms.
Alcohol
I practice medicine in New Orleans, a place where people enjoy life, music, food and yes, alcohol. While I don’t want to be a killjoy, people should know that alcohol is a direct poison to the gut lining, and is sometimes the sole reason why patients have ongoing GI symptoms.
I’ve seen several patients with longstanding GI symptoms that we were able to get mostly better, but because they continued to drink alcohol continued to have some symptoms and were not able to fully recover.
Food Sensitivities
Many patients come into my office having completed food sensitivity panels. I used to order these a lot from patients, until I observed that almost every test would come back with either wheat or dairy highlighted, along with a bunch of random foods, many of which people aren’t eating. Instead of asking patients to spend a few hundred dollars on an inaccurate test, I began having them try getting off gluten and dairy and watch their symptoms.
Hiatal Hernia
In this condition, a portion of the stomach slides upward above the diaphragm, where it causes symptoms of fullness, bloating, nausea and pain. The tricky thing about this condition is that the stomach can slide back down into place, which makes the symptoms come and go.
Here is a great review that describes some of the symptoms
“Hiatal hernias may present in variety of ways, both typical and atypical. Manifestations are dependent on the type and size of the hernia. Gastrointestinal manifestations are the most common, predominately with GERD and associated syndromes. Typical GERD presents with heartburn and regurgitation as part of a reflux syndrome. … Atypical GERD symptoms like cough, laryngitis, asthma, and dental erosions may exist with hiatal hernias. GERD symptoms are more often associated with type 1 hiatal hernias. Typical gastrointestinal obstructive symptoms of hiatal hernia manifest as nausea, bloating, emesis, dysphagia, early satiety, and postprandial fullness and pain in the epigastrium and chest.”
I estimate that about 5% of my patients with chronic GI symptoms have a sliding hiatal hernia as the cause of their trouble. Hiatal hernias are more common in patients with joint hypermobility because they have loose, stretchy connective tissue that isn’t quite as good at keeping the stomach down below the diaphragm, where it belongs.
Hernias are occasionally felt on a physical exam, and it’s always fun for me when a simple in office reduction earns immediate relief for a patient! If a hernia is found or suspected simple at home techniques are fantastic at reducing symptoms.
Bile Acid Malabsorption
In some studies, Bile Acid Malabsorption (BAM) or Bile Acid Diarrhea (BAD) is a more common cause of IBS than SIBO.
Bile acids are an important part of the GI physiology, and are critical to digestion. They are produced in the liver and released into the small intestines where they help break down fats, work as signaling molecules and even bind toxins. Because they are relatively difficult to make, the body has a process where the bile acids are reabsorbed later in the intestines after they’ve done their jobs. About 95% are sent back to the liver to be used again, while around 5% are eliminated in the stool.
For a variety of reasons (genetics, infections, SIBO, surgery, drugs like metformin) this normal process can become impaired causing more bile acids than normal to escape reabsorption and enter the large intestines where they cause diarrhea and abdominal pain, or the classic clinical signs of nighttime diarrhea.
BAD is treated with either prescription or supplements that help soak up the extra bile, reducing symptoms.
Medications
There are three classes of medications that are especially important to consider in any patient with IBS.
Antibiotics. It is extremely common for patients to report that their GI symptoms all began following antibiotic use. Two common scenarios that my patients report is when their GI problems followed a time in which they were given multiple courses of antibiotics for a urinary infection, or when patients are given longer term antibiotics like doxycycline or minocycline to control acne.
Proton Pump Inhibitors. These drugs (lansoprazole, omeprazole
pantoprazole) is commonly overprescribed by doctors, given over the course of decades when they meant for short term use of up to 12 weeks. Many of these drugs are available without prescription, and few are aware that lowering stomach acid can lead to GI infections, SIBO, dysbiosis and other problems.
Tricyclic Antidepressants. The class of medication including amitriptyline, nortriptyline, or doxepin are very effective anti-depressants and can help with sleep. However, it’s important to consider if your GI symptoms began after starting
Parasites & Infections
I first became interested in parasitology during a parasitology course I took at Notre Dame. I was hooked, and the whole world of parasitology was just creepy and fascinating to me. This interest led me to pursue a Master’s Degree in Public Health and Tropical Medicine at Tulane.
When I began my career, I assumed that the reason so many people had IBS must be parasites or infections that had gone under the radar. After all when I worked in the infectious disease wards, we would order what I saw as outdated microscopy studies for these patients, but now had access to DNA based testing. As a result, I began to order a LOT of advanced stool studies on all sorts of different patients, but eventually had to concede that parasites are pretty rare. It’s not to say that it never happens, but there is a reason why I am usually working on the issues above with my patients rather than simply doling out anti-parasitic medications.
However, all that said, I paid a lot of money for that degree in Tropical Medicine, so let’s end on the one time that you should always consider parasites: when a patient diagnosed with Celiac Disease doesn’t respond to a gluten free diet!
Would you like more information, or to schedule an appointment?