13 Causes of IBS-D Most Doctors Never Test For (But Should)


Over 60 Million Americans are affected with Irritable Bowel Syndrome (IBS). IBS-D is when it’s diarrhea-predominant IBS. In other words, if you suffer from diarrhea or loose stools weekly, then this is the label you get.

If you’re anything like me, you were probably told to supplement with fiber and prescription drugs. If you’re lucky, your doctor might have mentioned that food changes could help. I wasn’t and the several doctors I saw said what I ate didn’t matter. But after a few years of choking down Metamucil® and spending way too much time in the bathroom, I decided I didn’t want this “life sentence.”

The medical community is now learning that IBS is a diagnosis by exclusion. It puts people in a box but delivers nothing of value to the patient. IBS-D is a syndrome… not an actual disease. A label makes this group of symptoms easier to talk about but actually does a major disservice to patients.

Regardless of what a doctor has told you, it’s not “all in your head,” “not normal”, and Food DOES Matter. A doctor who’s interested in fixing you will be willing to spend the resources necessary to figure out the real cause of your recurring diarrhea.

IBS is Real and Can Lock You in Your Home

When you are having diarrhea, it’s pretty hard to do much of anything. You’re confined to a small radius around a toilet. Hopefully you have family or friends who can help out. If you have IBS-D, it’s likely you spend several hours a day in the bathroom, are scared that every fart might give you more than you bargained for and you’ve probably skipped several social events because you were scared how your stomach would respond.

Once I learned that IBS wasn’t actually normal and that people had cured themselves, I got kind of mad. Then I got resolute, I wanted to know how to make sure this stopped and never happened again.

How Would You Know If You Have IBS-D?

An IBS-D diagnosis is based on chronic diarrhea or altered bowel habits towards loose and watery stools. It’s also very likely that you suffer from abdominal pain, bloating, gas, and other gut pain. If you suffer slower motility and tend to be more constipated then it’s called IBS-C.

Common conventional medical practice is for a doctor to rule out other inflammatory bowel or organ conditions like Crohn’s disease or stomach ulcers. The Merck Manual suggests that diet can bring relief (gasp…) and also antidiarrheal drugs and antidepressants (seriously!?) as ways to treat IBS-D. Of course, any conventional treatment guide will mention fiber, laxatives and exercise as helpful but the reality is none of these actually solve the underlying problem. And for most people these options don’t offer much relief from the symptoms.

When I was ready for a different opinion, I wish I would have found a resource like this. Below are 13 common root causes of your chronic diarrhea and a few ideas on how you can rule them out. The point is: you have the power to change your health. But it starts with you first bringing these ideas to your doctor. Then, if he/she is unwilling to help you can find a better one on our practitioners page.

13 Root Causes of IBS-D

The root causes of IBS-D are actual problems that, until corrected, will continue to cause diarrhea and can lead to further health decline. This list is in no particular order and if need be could be printed to take to your next doctor’s appointment.

1 – Gut Dysbiosis: Is simply a condition in which the gut flora is disrupted.

Patient Translation: You have a bug problem in your gut. Each of us has over 100 trillion bacteria in our intestines and they live in a very complex and unique community. What we know at this point is if you upset that community, you hurt your health. And if bad bacteria, yeast or parasites take over it can result in diarrhea, constipation, gas, bloating, etc.

What to Do About It: The first step is to get a snapshot of what is actually happening down there. A very broad and in-depth stool test will be the ticket you need to figure out what is happening. We recommend 2 stool tests: A BioHealth #401 GI pathogen screen and Doctor’s Data Parasitology X3.

2 – Carbohydrate Malabsorption: The poly- and disaccharide carbohydrates you’re eating are not being broken down normally and are causing digestive problems.

Patient Translation: The complex carbohydrates (wheat, rice, quinoa, etc) you’ve been told are good for your health are actually causing gas, diarrhea, bloating and other GI problems. Over the course of our lives, toxins, antibiotics, bad bugs, stress and many other problems damage the intestine’s ability to digest food. When a damaged gut lining can’t split sugar molecules like it normally should, these molecules end up sitting around in the small intestine, not being absorbed by the body, and provide a great food source for bacteria and other organisms that shouldn’t eat them.

What to Do About It: The Specific Carbohydrate Diet was designed to combat this problem. You could try the diet first, or you can ask your doctor for lactose and or fructose breath tests. A positive result will determine if you do have some deficiency in the digestion of carbohydrates.

3 – Dairy Intolerance: Inability to properly digest and assimilate cow, goat, or sheep milk products.

Patient Translation: You cannot properly digest either the carbohydrate and/or protein contained in milk products. This causes symptoms like diarrhea, gas, or bloating. The carbohydrate is lactose, and most people are familiar with Lactose Intolerance. There is a major marketing movement by corporations to create lactose-free products… the problem is that just as many people cannot tolerate the protein in dairy called casein.

What to Do About It: You can stop eating all dairy and see if you notice any changes. You can also ask your doctor for two tests to rule this out (skip the skin allergy stuff, and regular blood testing it’s not reliable). The first test is to check lactose tolerance, using a breath test. The 2nd test is an Enterolabs test to check your ability to handle the casein protein.

4 – Gluten Sensitivity: New research shows that a group of people still have measurable inflammatory reactions to wheat even though they are negative for Celiac disease.

Patient Translation: Wheat contains many problematic proteins and chemicals that can cause significant diarrhea, brain and skin issues. It’s not just Celiac disease anymore. Research is still emerging, but suffice to say this is a much bigger problem than most thought.

What to Do About It: Get a saliva IgA test, Celiac blood tests, and if you really want to rule it out get this Cyrex Lab #3 to check to make sure all forms of wheat are okay for you.

5 – Celiac Disease: An autoimmune condition in which the villi of the small intestine get flattened/destroyed causing recurring diarrhea, loose stools and many other non-GI health problems.

Patient Translation: For a Celiac, their small intestine is damaged to a degree in which it makes it very hard to digest and absorb foods. Wheat will continue to damage the gut wall if it is eaten and create further autoimmunity. Actually, all grains contain a toxic component very close to wheat that is likely problematic to these people.

What to Do About It: Ask your doctor to rule this out with an endoscopy taking a biopsy of the villi. The truth is it’s not just about wheat, so while you’re waiting stop eating all grains.

6 – Crohn’s Disease: Is an inflammatory bowel disease that can be found from the mouth to the anus and is characterized by patchy spots of inflammation.

Patient Translation: Crohn’s disease can literally affect any area of the digestive tract and comes in several forms. What is shared among these are patches of high inflammation. These areas can be deep into the tissue or just surface level. Most people have symptoms of recurring diarrhea that can be mild to violent.

What to Do About It: If after reading about Crohn’s you want to rule it out, ask your doctor for an endoscopy and colonoscopy.

7 – Ulcerative Colitis: Another major inflammatory bowel disease usually located in the large intestine.

Patient Translation: Ulcerative Colitis is usually defined by wounds that do not heal (hence the name Ulcer-ative) in the large intestine. Most patients with Ulcerative Colitis have diarrhea and other abdominal pains. The loose stools or diarrhea can be mild to violent.

What to Do About It: Ask your doctor for a colonoscopy, which will be needed to rule it out.

8 – Small Intestinal Bacterial Overgrowth (SIBO): Is an overgrowth of bacteria in the small intestine.

Patient Translation: Bacteria are normal to the intestines, but not in high numbers in the small intestine (the majority is supposed to be in the large intestine). Due to a number of reasons, sometimes they creep out and make a home in the small intestine. Here they have free reign on the place and cause all kinds of trouble.

What to Do About It: Ask your doctor for either a 3-hour lactulose breath test (standard) or an Organix Comprehensive Profile – Urine test from Genova (newer).

9 – Antibiotic Use: Extended or repeated antibiotic use for any reason can lower the total number of bacteria and lower the number of bacteria species that live in a normal healthy digestive tract.

Patient Translation: Antibiotics are not targeted missiles, instead they are like massive nuclear bombs for all bacteria in the body. So, if you get a sinus infection, the antibiotic helps treat the infection. However, studies show that it also damages your gut flora, potentially long-term on every single use.

What to Do About It: The first step is to stop using them unless it is a life-threatening situation. The second step is getting a good idea about how healthy your gut really is. We recommend 2 stool tests: Bio Health 401H GI pathogen screen and Doctor’s Data Parasitology X3.

10 – Probiotics: Some people are intolerant to the probiotic bacteria they are supplementing with causing repeated loose stools or diarrhea.

Patient Translation: Probiotics are extremely helpful for almost everyone, unless the kind you’re taking is causing you GI problems. How could this be? Well, the strain in the supplement could be your enemy, the fillers, the capsule or supplementing bacteria to a gut that isn’t ready.

What to Do About It: If you’re still having diarrhea and you’ve tried several other tweaks to stop the diarrhea, think about stopping your probiotics for 7 days and see what happens. Try eating fermented foods instead.

11 – Egg Intolerance: Due to a leaky gut, the body can mount an immune response to egg, causing digestive issues and inflammation.

Patient Translation: Eggs have the potential to cause problems for people who are susceptible to them. They contain the protein albumin that the body will sometimes, in a state of sickness, mount a reaction to. When this happens, you get sicker and feel bad. Oftentimes, these people will get diarrhea several hours after eating eggs, but it could even take up to several days.

What to Do About It: You can get tested to see if you are mounting a response to egg, but that test doesn’t tell you much more than if you stop eating egg and feel better. Try removing egg from your diet for 4 days and see how you feel.

12 – Low Stomach AcidHypochlorhydria or achlorhydria are cases in which the stomach doesn’t produce enough acid in response to the food eaten. This disrupts digestion right from the beginning and can cause GI distress.

Patient Translation: If your stomach doesn’t’ make enough acid to digest the food you eat, then you won’t digest it. When you don’t digest your food, it can ferment and the wrong bugs can feed on it or it can get flushed out of the system because the body thinks something is wrong.

What to Do About It: The first step is to test for low stomach acid. If possible, get a Heidelberg test done for the best accuracy and find out exactly what is going on.

13 – Chronic Stress: The body’s stress response happens whether the stressor is an emotion, a thought, an email or a tiger. The response is a chemical process that can cause an increase in inflammation over a long period of time.

Patient Translation: Stress is normal, but it’s not supposed to happen all day long. In today’s environment, the human body is usually outmatched and thinks we are always fighting life and death scenarios. This causes the stress chemicals to always be high and deplete our body’s ability to heal and reduce inflammation. Chronic stress or even single high-stress events have significant stomach impact and can cause loose stools, diarrhea or pain.

What to Do About It: This should be checked for almost everyone. Unless you’re actively managing your stress in today’s world, you’re almost guaranteed to be chronically stressed. Ask your doctor for a BioHealth #201 Functional Adrenal Stress profile.

The One Step That Helps Everyone Suffering From Diarrhea

There is one common change that will help stop IBS-D, regardless of the root cause.

And that is changing the foods you eat.

The Specific Carbohydrate Diet gave me results in less than a week and I haven’t looked back since. You still should invest the time and effort to get the testing done that I’ve listed above, though. But while you’re waiting, if you’re sick of the pain then change the number one thing you have control over – what you eat.

To get started, you can download our free quick start guide here.


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