Published April 30 2018
Millions of people suffer from chronic diarrhea each year, including many with thyroid and autoimmune thyroid conditions. Although this is more common in those with hyperthyroid conditions due to the elevated thyroid hormone levels, some people with hypothyroidism and Hashimoto’s experience diarrhea as well. In this article I will discuss some of the causes of both acute and chronic diarrhea, the conventional treatment methods, and some natural treatment options.
Before discussing some of the common causes of diarrhea, let’s first discuss the definition of diarrhea. Diarrhea is defined as an increase in stool frequency, liquidity, or volume (1) [1]. A more objective definition is passing a stool weight or volume greater than 200 grams or 200 mL per 24 hour period (1) [1]. Fortunately most cases of diarrhea will self resolve, although approximately 5% of people in the United States will experience chronic diarrhea. As for the difference between acute and chronic diarrhea, acute diarrhea lasts 2 weeks or less, while chronic diarrhea is defined by liquid stools lasting longer than 4 weeks. Persistent diarrhea is characterized as a duration from 2 to 4 weeks, and this is also usually caused by pathogens such as Cryptosporidium, Giardia lamblia, and bacteria in the small intestine.
Regarding the mechanism of diarrhea, this involves incomplete absorption of water from intestinal luminal contents (1) [1]. So with diarrhea there is altered intestinal water and electrolyte transport. There are essentially three different types of diarrhea (1) [1]:
1. Inflammatory diarrhea. This type of diarrhea is usually characterized by bloody stools, and it can also be accompanied by fever or abdominal pain. Elevated inflammatory markers [2] are commonly present, such as C-reactive protein (CRP), calprotectin, and/or lactoferrin.
2. Fatty diarrhea. Fatty diarrhea usually involves weight loss, along with greasy or bulky stools. Fatty diarrhea is associated with malabsorption and maldigestion. If you’re wondering what the difference is between the two, fat maldigestion involves problems breaking down fat, which can happen if someone has a deficiency of digestive enzymes or inadequate bile acid concentration. On the other hand, fat malabsorption is usually caused by mucosal diseases, such as Celiac disease [3] or Crohn’s disease, although there can be other causes as well.
3. Watery diarrhea. This type of diarrhea can either be osmotic or secretory. Osmotic diarrhea is caused by the ingestion of poorly absorbed ions or sugars, while secretory diarrhea is caused by the disruption of epithelial electrolyte transport.
Fecal Incontinence vs. Diarrhea
It’s also important to distinguish fecal incontinence from diarrhea, as incontinence involves the involuntary release of rectal contents. This typically is due to dysfunction of the anal sphincter. Fecal impaction can also be misinterpreted as diarrhea, and this actually is found in those with chronic constipation. What happens is that some people with chronic constipation are unable to expel feces, and as a result, rectal distension causes relaxation of the internal anal sphincter, which in turn leads to the development of secretions, which may be reported as diarrhea.
10 Common Causes of Diarrhea
Let’s go ahead and take a look at 10 common causes of diarrhea:
Common Cause #1: Infections. Bacteria, viruses, and parasites can all cause diarrhea. In the United States and other developed nations, rotaviruses and norvoviruses are the most common cause of diarrhea. Norovirus is the leading cause of gastroenteritis, and affects 23 million people per year in the United States (2) [4]. Although viruses can be spread via contaminated food or water, they are most commonly passed from person-to-person.
As for bacterial causes of diarrhea, some of the common pathogens involved include Campylobacter, Salmonella, Shigella, and enterohemorrhagic E. coli (EHEC).
Giardia and Cryptosporidium are the most common enteric protozoan infections worldwide (3) [5]. Many are also infected by Entaemoeba histolytica. Other parasitic infections include Blastocystis hominis, microsporidia (Enterocytozoon spp, Encephalitozoon spp), Isospora, Cyclospora, Schistosoma and Strongyloides.
What You Need To Know About Traveler’s Diarrhea
Many people reading this have heard of “Traveler’s diarrhea”, and this is frequently acquired during the first two to three weeks of travel, and is usually caused by the ingestion of contaminated foods, and sometimes water. In most cases Traveler’s diarrhea will self-resolve, although this isn’t always the case. Some of the high-risk areas of the world include Africa (excluding South Africa), South and Central America (excluding Chile and Argentina), as well as the majority of the Middle East, Southern and Southeast Asia, and Oceana.
As for the pathogens involved, it can be caused by bacteria, viruses, or parasites. Enterotoxigenic Escherichia coli (ETEC) and enteroaggregative E. coli (EAEC) are the most common bacterial pathogens involved (4) [6]. Norovirus and rotavirus are the most common viruses associated with traveler’s diarrhea (5) [7]. Giardia duodenalis and Entamoeba histolytica are the most common parasites involved with this condition (5) [7].
How Can Enteric Infections Be Diagnosed?
Enteric infections refer to infections that are located in the intestines, and bacterial cultures and microscopy to detect ova and parasites are diagnostic methods that have been used for many years. While these methods are still utilized by some labs, the sensitivity of microscopy depends on numerous factors, including the burden of infection, the freshness of the specimen, and how experienced the clinician is who is performing the microscopy. Trichrome stains are sometimes used to improve the detection of specific organisms, as they increase the contrast of microscopic features in cells and tissues.
Common Cause #2: Food. Eating raw or undercooked meats or seafood is another potential cause of diarrhea. Surprisingly, one study showed that foods prepared at home had the highest levels of bacterial contamination. Visiting foreign students eating more than 80% of their meals at their host families’ homes had the highest rates of traveler’s diarrhea (6) [8]. It’s also worth mentioning that while parasites are commonly blamed for Traveler’s diarrhea, bacteria are actually a more common cause.
In some people, eating high FODMAP foods can cause diarrhea. This is common in those people with IBS-D and small intestinal bacterial overgrowth (SIBO). A few years ago I wrote a blog post on the low FODMAP diet [9] that you might want to check out.
Common Cause #3: Medication. Some of the medications that commonly cause diarrhea include antacids, antibiotics, proton pump inhibitors, SSRIs, and NSAIDs. Medications that include magnesium can also cause diarrhea.
Common Cause #4: Bile acid malabsorption. Bile acid malabsorption is usually caused by dysregulation of the enterohepatic recycling of bile acids and of bile acid production (7) [10]. Under normal circumstances, bile acid production is regulated by the bile acid receptor FXR, but excessive levels of bile acids can cause diarrhea through multiple mechanisms. Some of the potential causes of bile acid malabsorption include Celiac disease, gall bladder surgery, SIBO, and radiation injury (7) [10].
Common Cause #5: Small Intestinal Bacterial Overgrowth (SIBO). I’ve written separate articles on SIBO [11] in the past, and elevated hydrogen levels on a breath test is commonly associated with diarrhea. On the other hand, elevated methane is more commonly associated with constipation. However, this doesn’t mean that everyone with elevated hydrogen levels will experience diarrhea, although if this correlation is made then in most cases, lowering these levels will help with the diarrhea. This is easier said than done, as SIBO can be very challenging to treat.
Common Cause #6: Inflammatory Bowel Disease [12]. Those with Crohn’s disease and ulcerative colitis can present with numerous symptoms including abdominal pain, weight loss, and diarrhea. It’s not uncommon for those with inflammatory bowel disease to have blood in the stool.
Common Cause #7: Celiac Disease. This is an autoimmune condition involving gluten, and although not everyone with this condition experiences diarrhea, this can occur due to the malabsorption commonly associated with this condition. The malabsorption is caused by damage to the cells of the small intestine, and avoiding gluten is necessary for healing of the small intestine to take place.
Common Cause #8: Chronic pancreatitis. Pancreatitis is when there is inflammation of the pancreas, and chronic pancreatitis occurs due to irreversible scarring of the pancreas, which is caused by prolonged inflammation (8) [13]. Malabsorption is commonly due to the decreased ability to secrete a sufficient amount of pancreatic enzymes, including pancreatic lipase, and this can lead to steatorrhea, bloating, indigestion, dyspepsia, and diarrhea (8) [13].
Common Cause #9: Disaccharidase deficiency. Disaccharidases are enzymes that break down complex sugars (disaccharides) into simple sugars. An example of a disaccharide is lactose, which is a sugar found in dairy products. So when someone has a “lactose intolerance”, this isn’t the same as a dairy allergy or sensitivity, but instead is caused by a deficiency of lactase, which is the enzyme needed to break down lactose. The amount of lactose that can be digested varies, and genetics do play a role.
Common Cause #10: Hyperthyroidism. Since I focus on helping people with thyroid and autoimmune thyroid conditions, you might wonder why I didn’t bring hyperthyroidism up first as a cause of diarrhea. The reason why this is listed last is because out of all of the causes of diarrhea listed here, hyperthyroidism is one of the less frequent causes. First of all, only a small percentage of the population has hyperthyroidism. In addition, most of the people I work with who have hyperthyroidism and Graves’ disease don’t have “full blown” diarrhea. It’s more likely for people with hyperthyroidism to have loose stools, and some people actually experience constipation, especially those who are taking antithyroid medication [14] such as Methimazole.
Other Causes of Diarrhea
In addition to the causes listed above, some other causes of diarrhea include radiation enteritis, lymphoma, pancreatic carcinoma, diabetes [15], fructose malabsorption, and Addison’s disease.
Characteristics Associated With Diarrhea
Below are some of the different characteristics people can experience when they have diarrhea:
Bloody diarrhea. This is usually associated with certain types of infections, including Shiga toxin-producing E. coli (STEC), shigella, and Entaemoeba histolytica.
Abdominal pain. This is common with Yersinia and Clostridium difficile (C. diff).
Dysentery. This is common with Shigella and Campylobacter.
Wasting. This is common with Giardia and Cryptosporidium.
Fecal inflammation. This is common with Shigella, Campylobacter, Salmonella, and some E. coli and C. diff infections.
Conventional Treatment Methods for Chronic Diarrhea
As for the conventional treatment methods utilized, antidiarrheal agents might be used for some cases of chronic diarrhea. Opiate antidiarrheal drugs are frequently used, as they slow motility and increase absorption (9) [16]. There are other antidiarrheal drugs that can work on other regulatory pathways in the gut or on improving absorption (9) [16].
One of the first things that need to be assessed when dealing with diarrhea is the amount of dehydration. This can depend on how long the person has had diarrhea for and how alert they are. Mucous membrane dryness, sunken eyes, and postural hypotension all indicate moderate or severe hypovalemia and dehydration. When dehydration has been confirmed the person needs to be given fluids and electrolytes, and sometimes they are also given antidiarrheal agents such as bismuth subsalicylate (i.e. Pepto-Bismol) or loperamide.
In cases of bile acid malabsorption, cholestyramine is usually administered. This is a bile sequestering agent, and it’s important to know that this can also bind to other drugs you are taking. This includes levothyroxine (10) [17], and as a result, if you take cholestyramine you should take other types of medication either one hour before or four hours after. Cholestyramine may also interfere with the absorption of fat-soluble vitamins, which include vitamins A, D, E, and K.
As for those with hyperthyroidism and Graves’ disease, when I was doing research for this article I discovered that cholestyramine has been shown to decrease thyroid hormone level when added to antithyroid medications such as Methimazole (11) [18] (12) [18]. So while it can have a negative effect when taken at the same time as thyroid hormone replacement, by binding to thyroid hormones it might be another treatment option, especially for those who don’t respond to antithyroid medication.
Natural Treatment Solutions For Chronic Diarrhea
Remember that diarrhea itself isn’t a condition, but instead is a symptom. That being said, the obvious goal should be to address the cause of the diarrhea. If someone has an infection leading to acute diarrhea, frequently no treatment is necessary, as the diarrhea will usually self-resolve. However, if chronic diarrhea occurs in the presence of an infection and treatment is necessary then there are natural agents that can eradicate infections, which I have discussed in other articles and blog posts.
If food poisoning is the cause of the diarrhea, then in this case the diarrhea will usually self resolve within a few days. However, in some cases this can damage the migrating motor complex and lead to IBS-D. This in turn can also set the stage for small intestinal bacterial overgrowth. For more information on this I’d check out the past article I wrote on SIBO and thyroid autoimmunity [19].
If an offending food is causing diarrhea, such as gluten or lactose, then of course this food should be avoided. Sometimes multiple foods need to be avoided, which frequently is the case if someone has a condition such as IBS-D/SIBO.
It’s also worth mentioning that certain strains of probiotics have been shown to help reduce the duration of diarrhea. Lactobacillus rhamnosus GG and Saccharomyces boulardii [20] have been shown in the research to be effective in some cases of diarrhea (13) [21]. Some people also have achieved relief from diarrhea from taking very high doses of probiotics (i.e. 300+ billion CFU).
Using The 5-R Protocol To Reverse Chronic Diarrhea
Most cases of chronic diarrhea can be cured by incorporating the 5-R protocol. This involves removal the exacerbating agent (i.e. food, infection, chemical), replacing enzymes, reinoculation through prebiotics and probiotics, repairing the gut, and rebalancing the body. I realize this is easier said than done, but it’s not uncommon for people with chronic diarrhea to fail to remove the factor that is causing the diarrhea, and instead to focus on taking things to stop the diarrhea, including prescription or natural antidiarrheal agents and probiotics. Of course one reason for this is because at times it can be challenging to find out what exactly is causing the chronic diarrhea, and hopefully the information in this article will help you with this.
While the obvious goal should be to detect and address the cause of the diarrhea, in some cases it is a good idea to take antidiarrheal agents. One study showed that the leaf extract of J. schimperiana has antidiarrheal activity, as it reduces total fecal output and diarrheal drops, intestinal fluid accumulation, and gastrointestinal motility (14) [22]. Another study showed that Krisanaklan might also have antisecretory effects and therefore help with diarrhea (15) [23]. Here are some additional agents which might help with chronic diarrhea:
Ginger. This herb is known for its anti-inflammatory benefits, but it also has antidiarrheal activity, which is probably due to the active component zingerone (16) [24].
Licorice. Glycyrrhizin is the principal component of this herb, and while I commonly recommend licorice root for those with low cortisol levels, research shows that it is capable of suppressing diarrhea (17) [25].
Berberine. Recent studies indicate the berberine can inhibit intestinal fluid accumulation and ion secretion (18) [26], and has other actions which may contribute to an antidiarrheal effect (19) [27].
Cocoa. I’m sure many reading this will be pleased to know that cocoa can help with diarrhea in some cases. Reports dating back to the 15th century show that traditional cocoa preparations were used by indigenous people of Central America to treat childhood diarrhea and other intestinal ailments (20) [28].
Fenugreek. There is evidence that fenugreek can help with diarrhea (21) [29].
In summary, millions of people suffer from chronic diarrhea each year, and this includes people with thyroid and autoimmune thyroid conditions. The three types of diarrhea include inflammatory diarrhea, fatty diarrhea, and watery diarrhea. Some of the different cause of diarrhea include infections, food poisoning, medication, bile acid malabsorption, SIBO, inflammatory bowel disease, Celiac disease, chronic pancreatitis, disaccharidase deficiency, and hyperthyroidism. Conventional treatment options include antidiarrheal agents, cholestyramine for bile acid malabsorption, and making sure the person is well hydrated. Some natural agents with antidiarrheal effects include ginger, licorice root, berberine, cocoa, and fenugreek. The obvious goal of natural treatment methods is to find out the underlying cause of the chronic diarrhea and then address it.