Chronic Diarrhea

By Sanaz Majd, MD

About 3-5% of the population reportedly suffers from chronic diarrhea, which is defined as a persistent change in stool consistency ranging from loose to watery stools. For some, it is pervasive and daily, while for others it is intermittent but still frequent enough to impair quality of life.

Let’s review some of the most common causes.

Medication Side Effects:

Antibiotics:

Antibiotics kill bacteria and this sometimes includes the “good” bacteria in our gut that is maintaining that equilibrium that keeps our stomach and intestines in check. Therefore, antibiotics can interfere with this harmonious balance and result in uncomfortable diarrhea.

Of course, diarrhea is only one of the numerous risks of unnecessary antibiotic overuse, which is currently of epidemic proportions, having led to the immense antibiotic resistance that the U.S. is facing. Hence, its use should be limited to true bacterial infections, such as for urinary tract infections, cellulitis (skin infections), bacterial pneumonias, etc.

Antibiotics do not kill viruses and, hence, are not indicated for upper respiratory infections or the flu. Unfortunately, they are often erroneously prescribed for “sinusitis,” which is much more often caused by viruses and less commonly by bacteria.

Metformin:

This is a very commonly used, first-line generic medication used to treat diabetes and sometimes prediabetes and polycystic ovarian syndrome (PCOS). Its gastrointestinal (GI) side effects sometimes limits its use in some people, as it can cause diarrhea and abdominal discomfort, most especially in those who take it without food. However, the side effects do tend to dissipate in most people within a few weeks after initiation as the body adapts.

NSAIDs:

Ibuprofen, Advil, Motrin, Aleve, Naproxen, and Meloxicam are all examples of non-steroidal anti-inflammatories (NSAIDS). They can irritate the stomach lining and diarrhea is also a reported side effect as a result. For those who are sensitive to its effects, acetaminophen may be an option, as it is not an NSAID but a pain reliever and fever reducer.

Magnesium Products:

Numerous over-the-counter medications contain magnesium, including Milk of Magnesia and Mylanta used to treat indigestion, certain laxatives, and supplements, including some that contain calcium. However, diarrhea is one of its most commonly reported side effects of magnesium.

Irritable Bowel Syndrome (IBS):

By far one of the top causes of chronic intermittent diarrhea is IBS. I’ve covered this topic in much greater detail in a recent Peyk article, but these patients tend to experience constipation, diarrhea, or both, associated with some type of abdominal discomfort on and off throughout their lives. There is often a mental health component (but not always), as stress, anxiety, and depression are common triggers of the symptoms, as are certain foods.

Infections:

Most cases of infectious diarrhea are actually viral, and tend to resolve on their own without treatment. But here are the top causes of non-viral infectious diarrhea, which tend to cause more severe diarrhea than its viral counterparts and they also tend to be more acute and less chronic:

Clostridium Difficile:

“C. diff” is a bacteria that can overgrow in our GI system when given the opportunity. Antibiotic use is the most common culprit—another reason to curtail unnecessary antibiotic use. It achieves this by destroying the good bacteria and allowing C. diff to overgrow and set up shop in your GI system.

People who are immunocompromised can more easily contract it, such as the elderly, hospitalized patients, those on chemo, or those on medications used to treat autoimmune disorders such as rheumatoid arthritis, psoriasis, and lupus. In addition, there are reports that certain medications that suppress stomach acid secretion can also predispose to C. diff—and there are many people who routinely take this group of drugs, as they are readily available over the counter. These medications include omeprazole, pantoprazole, famotidine, and ranitidine.

Other Bacteria:

Campylobacter, Salmonella, and Shigella are examples of other bacterial infections of the gut that can cause diarrhea, albeit more acute. These infections are less common in the United States and more prevalent in those who have had recent international travel. However, occasional reported outbreaks have occurred with contaminated vegetables, meat, poultry, eggs, and unpasteurized milk in the U.S.; these outbreaks can also spread more quickly in daycare centers and nursing homes.

Parasites:

Protozoa, including Giardia and Cryptosporidium, are parasitic GI infections that are typically either food- or water-borne. They are less common in the U.S. and more prevalent in those who travel internationally, including to nearby Mexico. But there have been reported outbreaks in those who consume water sources while hiking and camping in the U.S., in addition to daycare centers and public swimming pools.

Medical Conditions:

Celiac Disease:

Celiac disease is a hereditary autoimmune condition, which means that the body erroneously regards certain parts of itself as “foreign” and mounts an immune attack. This is often in response to the consumption of gluten, which inflames the small intestine and results in diarrhea. Celiac disease is more common in those of European descent, but also increasingly found in those from India, Northern China, and the Middle East, as well.

Note that gluten “intolerance” is not the same thing as true celiac disease. Those with intolerance do not mount an immune-mediated response, but simply fare better without gluten in their diet. The theory is that it is due to the concomitant absence of “fructans” which often accompany foods higher in gluten.

Inflammatory Bowel Disease (IBD):

Crohn’s disease and Ulcerative Colitis are the two IBD subsets—they often have a genetic component and tend to run in families. People who have these conditions begin to experience symptoms rather early on in life, during their teens, twenties, and thirties. And they may also have other accompanying symptoms, such as fever, joint pain, mouth ulcers, and unexplained eye redness. They also tend to report more bloody diarrhea, although not always.

Hyperthyroidism:

Although uncommon, a hyperactive thyroid can also trigger diarrhea in some people. The condition can also cause elevated heart rate and blood pressure, heart palpitations, and increased anxiety. There tends to be a genetic component as it is often hereditary. A simple blood test can screen for hyperthyroidism.

Dietary:

Food intolerance can also cause chronic diarrhea. Not everyone is the same, however, and may also differ in the limit of tolerance of a specific food item consumed. For instance, you may tolerate a little bit of milk in your cereal, but an entire cup of milk may drive you to the nearest toilet.

Here are some common culprits:

sugar substitutes—these include diet sodas, sugar-free sweets, and sugar substitutes that are added to your coffee or chaiee
lactase—this includes anything derived from dairy cows, including milk, ice cream, cheese, and yogurt
caffeine—besides the obvious coffee, do not forget chaiee, chocolate, and sodas
alcohol

When Should You Worry About Chronic Diarrhea?

Most chronic diarrhea is benign and self-resolving. However, the following red flag features make it more concerning:

severe diarrhea
unintentional weight loss
family history of Inflammatory Bowel Disease (like Crohn’s and Ulcerative Colitis), celiac disease, or colon cancer
bloody stools or black stools
severe abdominal pain

Diagnostic Tests

If diarrhea is persistent, recurrent, or bothersome in any way, your doctor may initiate a workup to discover the cause. Here are some of the tests that may help shed light on your symptoms:

CBC—this would help determine if there is accompanying anemia, which may be present in those with celiac disease or those with bleeding in the stool, even if microscopic
TSH—this is to rule out hyperthyroidism
Electrolytes—if diarrhea is significant, it can sometimes cause electrolyte imbalances
Celiac panel—this would help rule out celiac disease, as long as there has not been any gluten restriction in the diet, which can mask results and yield a false negative
Stool studies—they can screen for bacterial causes, including C. diff, and also ova and parasites; if there is a concern for possible blood in the stool, a stool test for blood may also be useful
Colonoscopy—depending on the symptoms and other work up results, your doctor may consider a referral to a gastroenterologist for a possible colonoscopy, which is a camera scope that is placed through the rectum to view the lining of the colon.

Sanaz Majd, MD, is a board-certified Family Medicine physician and host of the Majd MD YouTube channel, reviewing the latest medical topics and headlines: www.youtube.com/MajdMD. You can also follow her on Facebook or Instagram: @SMajdMD.