What Causes Persistent Diarrhea? Relief & Treatment

Key takeaways:

• Diarrhea can be caused by both functional and organic disorders;
• Some symptoms may require a more urgent evaluation by a healthcare professional or referral to a specialist known as a gastroenterologist;
• Other factors that may play a role in chronic diarrhea include socioeconomic status, geographic location, and recent travel history.

Diarrhea can be extremely frustrating, especially when you’ve suffered from it for a long time. Causes of chronic (persistent) diarrhea vary based on age, family history, and previous medical history, among other factors.

Fortunately, there are treatment options you can try at home – but it’s important to know that some causes of diarrhea may require urgent evaluation from a healthcare professional. If you experience alarming symptoms, please speak with your healthcare provider.

What is chronic diarrhea?

Diarrhea is defined as a change in bowel movement, also known as stool. Specifically, the consistency of stool changes from normal to looser and becomes more frequent (more than three stools daily).

A tool known as the Bristol stool chart can help you classify the consistency of your stool. Stool consistency between types 5 and 7 on the Bristol chart meets the criteria of diarrhea. When that condition persists for at least four weeks, it’s classified as chronic diarrhea.

When should you worry about chronic diarrhea?

As frustrating as chronic diarrhea can be, it isn’t always something to worry about. In some cases, however, concern is justified. There are multiple factors (known as alarm features) that could indicate a serious problem at the root of chronic diarrhea. These include:

• Onset of symptoms in someone 50+ years old
• Bleeding, or bright-red or maroon-colored stools
• Pain during the night or stools overnight that cause you to wake from sleep
• Abdominal pain or fever
• Unexplained weight loss
• Family history of inflammatory bowel disease (IBD) or colorectal cancer
• Abnormalities noted in bloodwork

Common causes of chronic or persistent diarrhea

Causes of chronic diarrhea can be divided into two main categories: functional and organic. Functional causes are those without an associated physiologic, structural, or biochemical abnormality. That refers to diarrhea that doesn’t have an obvious cause, such as one that can be diagnosed with a blood test. In contrast, organic causes of chronic diarrhea do have an associated physiologic, structural, or biochemical abnormality.

Following are some of the most common functional and organic causes of chronic diarrhea.

Irritable bowel syndrome

Irritable bowel syndrome (commonly known as IBS) is the most common functional disorder associated with chronic diarrhea. IBS symptoms are typically lower abdominal pain along with changes in stool pattern. These changes can vary from constipation to diarrhea and alternate between the two extremes.

In patients with IBS, chronic diarrhea often manifests as frequent loose stools that are small to moderate volume and typically occur in the morning or after eating. IBS patients also experience urgency, meaning a sudden need to use the bathroom. Even after a bowel movement, the urge may not go away. About half of IBS patients also notice mucus discharge in their stools. These symptoms are often worse when IBS patients are experiencing higher stress.

IBS is part of a spectrum, as multiple functional disorders are related to it. These disorders include functional diarrhea, IBS with predominant diarrhea, and IBS with mixed bowel habits. It’s important to note that “functional diarrhea” (the ongoing prevalence of loose stools) is a separate entity from IBS, as abdominal pain and bloating are not its primary symptoms.

Inflammatory bowel disease

The term inflammatory bowel disease (IBD) is used to refer to any intestinal disorder associated with intestinal inflammation. Most often, however, it refers to two conditions: ulcerative colitis and Crohn’s disease. Both of these conditions are caused by underlying inflammation in the intestines, and both can cause chronic diarrhea. How they differ is in the presenting history, symptoms, and associated disease course.

In most cases, symptoms for both ulcerative colitis and Crohn’s disease begin when patients are between 15 and 40 years old. Studies suggest, however, that there is another peak of diagnosis between the ages of 50 and 80 years old. IBD has a genetic component, as it typically runs in families, and certain populations are at greater risk of developing it.

Crohn’s disease can involve the entire gastrointestinal (GI) tract from the mouth to the anus. Typical symptoms include chronic diarrhea, abdominal pain, weight loss, and fever, although any (or all) of these symptoms can develop a long time before someone is diagnosed. GI blood loss is another possible symptom, although it is more common in ulcerative colitis. Patients with ulcerative colitis typically experience episodes of rectal bleeding, either bright-red stools or dark-colored/maroon stools.

One difference between ulcerative colitis and Crohn’s disease is where in the GI tract each occurs. Ulcerative colitis is limited to the rectum and distal portion of the colon, meaning the parts of the GI tract it affects work backward. Crohn’s disease can involve multiple portions of the gastrointestinal tract.

Malabsorption syndromes

Malabsorption syndromes are conditions that prevent the body from absorbing nutrients from foods or a specific type of food. These conditions include:

• Lactose intolerance, in which the body has trouble absorbing foods that contain lactose (such as dairy products);
• Celiac disease, in which the body has trouble absorbing foods with gluten;
• Small intestinal bacterial overgrowth (SIBO), in which different bacterial flora affect proper absorption of nutrients;
• Chronic pancreatitis, a chronic inflammation of the pancreas that affects its hormones and digestive function.

Along with chronic diarrhea, another possible symptom of malabsorptive disorders is pale, greasy, large-volume, and foul-smelling stools. Also, patients may notice that they are losing weight even though they’re eating an appropriate diet. All in all, clinical features of malabsorptive disorders vary based on the type.

Chronic infections

Although it is less common in the United States and other well-developed nations, some infections can cause chronic diarrhea. People with compromised immune systems are at higher risk of developing such infections, including Clostridium difficile (C. diff), Aeomonas, Plesiomonas, Campylobacteria, Giardia, and Cryptosporidium, among others. You may develop additional symptoms in cases of chronic infections (along with chronic diarrhea), such as fever.

The risk of chronic infections is increased if you have recently traveled to countries where the risk of developing such infections is higher.

Read our guides on causes and types of diarrhea for more.

How to treat chronic diarrhea

Given the wide variety of causes that may contribute to chronic diarrhea, there is not one single solution that will immediately fix your symptoms. Even so, there are over-the-counter and prescription medications that may help relieve your symptoms.

Treating chronic diarrhea with over-the-counter remedies

Since chronic diarrhea involves loose stools, remedies that help better form stools may be effective. Fiber supplements are an option, although fiber is best when naturally obtained through your diet. Eat fiber-rich foods such as beans, broccoli, whole grains, various fruits, and nuts. Also, it’s important to remember that there are two types of fiber: soluble and insoluble, so getting a mix of foods that contain both may help with your symptoms.

Over-the-counter medications, such as Pepto-Bismol, can help with chronic diarrhea. Keep in mind its side effects, however, such as constipation and dark-colored stools.

Minimizing stress

Stress can have a huge effect on your overall health and any health problems you may have, including chronic diarrhea.

As previously mentioned, stress can be a particular trigger for symptoms if you have IBS, although this is also true whether or not your symptoms are caused by a specific diagnosis. Making an effort to minimize stress in your life can have a positive influence on your health. This is especially true when combined with other lifestyle modifications such as getting plenty of sleep, staying active, and eating a nutritious diet.

Lactose-free diet and other dietary modifications

If you’re affected by chronic diarrhea after eating a specific food or type of food, you may benefit from dietary changes that involve reducing or eliminating those foods.

This can be especially beneficial if you have a malabsorption disorder, such as those previously discussed. You may find that keeping a food diary can help identify whether you may have a malabsorption disorder or merely an intolerance to certain foods. Be sure to speak with your healthcare provider about this.

Prescription medications for chronic diarrhea

There are numerous prescription drugs that your healthcare provider may recommend to help with your chronic diarrhea. One example is loperamide (also known as Imodium), which slows intestinal movement. Another possibility is cholestyramine, a bile acid-binding medication. One or more other medications may also be prescribed.

Common treatment of chronic diarrhea with a doctor’s guidance

Treatment of your chronic diarrhea will vary based on the underlying cause of your symptoms. Your healthcare provider can help identify what is causing them and use that to guide which medications or other treatment options are best suited to your personal needs.

When you should see a doctor about chronic diarrhea

Chronic diarrhea can be tough to cope with – and to understand. Although it may not be anything serious, it could be an underlying symptom of a health problem. Be sure to seek the advice of your healthcare provider for further evaluation and possible referral to a specialist like a gastroenterologist.

You should see a doctor if:

• Your symptoms occur more frequently or the volume of your bowel movements continues to increase despite the use of treatments
• You notice weight loss
• You have significant changes in appetite
• You have abdominal pain that’s getting worse
• You have any of the following alarm features: symptoms beginning after 50 years of age, rectal bleeding or black, tarry stools, pain or diarrhea during the night, fever, or first-degree relative with IBD or colorectal cancer

You should go to the emergency room if:

• You vomit up blood
• You notice bright red blood in your bowel movements
• You experience loss of control of your bladder or bowel
• You experience sudden dizziness that does not resolve
• You experience ongoing palpitations - the sensation of a racing heart, that does not resolve

Questions to ask your doctor about chronic diarrhea

• Should I get blood work, stool studies, or other tests for my chronic diarrhea?
• Would it be wise for me to get a CT or MRI?
• Is the sort of condition that merits an endoscopy, colonoscopy, or other diagnostic tests?
• What other treatment options or medications could help with my symptoms?

Frequently asked questions: chronic or persistent diarrhea

Chronic diarrhea is not a clear-cut topic, unfortunately. Everyone who has suffered through it wants it to go away, especially those who have dealt with it for a long time. Below are some frequently asked questions regarding chronic diarrhea.

What if you’re experiencing on-and-off chronic diarrhea?

It’s helpful to keep a diary in which you jot down your symptoms, especially if you notice a pattern of when they occur and for how long. If your symptoms haven’t been occurring persistently for four weeks or longer, it may be classified as intermittent diarrhea, rather than chronic diarrhea.

Is chronic diarrhea a sign of cancer or colon cancer?

Not necessarily – but it could be, particularly if it’s occurring with some previously mentioned alarm features. If you have a family history of cancer or colon cancer, please reach out to your doctor to discuss your symptoms.

What if you have diarrhea every day, but no other symptoms or illness?

If you don’t have any alarm features and are only experiencing ongoing diarrhea, start keeping track of the frequency, consistency, and volume of your bowel movements. This can help determine if there are any factors or patterns that need to be checked out.

Does stress cause chronic diarrhea?

Stress can cause chronic diarrhea and make it worse. It may not be the only reason for your symptoms, but it’s likely a contributing factor. Minimizing stress may help reduce or resolve your symptoms.

Controlling your chronic diarrhea

Having normal bowel movements plays an important role in your health and well-being – and coping with chronic diarrhea can make you feel miserable. By better understanding your symptoms, you’ll be able to take control of your health and know when you need to reach out to your healthcare provider for further evaluation.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Adam Carewe, MD.

Sources

Riddle, Mark S et al. “ACG Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults.” The American journal of gastroenterology vol. 111,5 (2016): 602-22. doi:10.1038/ajg.2016.126

Robyn. “Bristol Stool Chart.” Continence Foundation of Australia, February 9, 2024. www.continence.org.au/bristol-stool-chart.

Talley, N J et al. “Epidemiology of colonic symptoms and the irritable bowel syndrome.” Gastroenterology vol. 101,4 (1991): 927-34. doi:10.1016/0016-5085(91)90717-y