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Patient education: Chronic diarrhea in adults (Beyond the Basics)

J Thomas Lamont, MD
Section Editor
Lawrence S Friedman, MD
Deputy Editor
Shilpa Grover, MD, MPH, AGAF
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Chronic diarrhea is defined as loose stools that last for at least four weeks. This usually means three or more loose stools per day. There are many possible causes of chronic diarrhea. Treatment is aimed at correcting the cause of diarrhea (whenever possible), firming up loose stools, and dealing with any complications of diarrhea.

Chronic diarrhea can have a substantial impact on your quality of life and overall health. At its mildest, diarrhea is an inconvenience; at its worst, it may be disabling and even life threatening. Fortunately, effective treatments are available.

This article will focus on causes of chronic diarrhea in developed countries, such as the United States. More detailed information about chronic diarrhea in developed countries is available by subscription. (See "Approach to the adult with chronic diarrhea in resource-rich settings".)


A wide range of problems can cause chronic diarrhea; some of the most common causes include irritable bowel syndrome (IBS), inflammatory bowel disease (Crohn disease and ulcerative colitis), malabsorption syndromes in which food cannot be digested and absorbed, and chronic infections. There are also many other less common causes of chronic diarrhea.

Irritable bowel syndrome — Irritable bowel syndrome is one of the most common causes of chronic diarrhea. IBS can cause crampy abdominal pain and changes in bowel habits (diarrhea, constipation, or both). IBS can develop after having an infection. (See "Patient education: Irritable bowel syndrome (Beyond the Basics)".)

Inflammatory bowel disease — There are several types of inflammatory bowel disease, two of the most common of which are Crohn disease and ulcerative colitis. These conditions may develop when the body's immune system attacks parts of the digestive tract. (See "Patient education: Crohn disease (Beyond the Basics)" and "Patient education: Ulcerative colitis (Beyond the Basics)".)

Infections — Intestinal infections are a cause of chronic diarrhea. Infections that cause chronic diarrhea can be seen in people who travel or live in tropical or developing countries. Intestinal infections can also develop after eating contaminated food or drinking contaminated water or unpasteurized ("raw") milk. (See "Patient education: Food poisoning (foodborne illness) (Beyond the Basics)".)

Endocrine disorders — An overactive thyroid (hyperthyroidism) can cause chronic diarrhea and weight loss. Diabetes can cause chronic diarrhea if the nerves that supply the digestive tract are injured.

Food allergy or sensitivity — Food allergies and hypersensitivity can cause chronic diarrhea. People with celiac disease are sensitive to gluten, a major component of wheat flour which can cause diarrhea and weight loss. Patients with lactose intolerance develop diarrhea and gas when they ingest milk. (See "Patient education: Celiac disease in adults (Beyond the Basics)".)

Medicines — Medicines (prescription and nonprescription), herbs, and dietary supplements can cause diarrhea as a side effect. To determine if a medicine could be the cause of your diarrhea, review your list of medicines with your doctor, nurse, or pharmacist. This information may also be available on the medicine bottle or paperwork that comes with most prescriptions.


You should seek medical attention if you have loose or watery stools that last more than three or four weeks. You may need to be seen sooner than this if you have complications of diarrhea (eg, bloody diarrhea, fever, dehydration, or weight loss) or abdominal pain that interferes with your activities or prevents eating.

During your visit, it is important to mention when your diarrhea began, any recent changes in medicines or medical problems, and if you have had accidents (leaking or smearing of stool in the underwear). Also, provide your doctor with any information about foreign travel and if you are taking medicines for your diarrhea.

Tests — Blood, stool, and urine tests can help to find the underlying cause of diarrhea. Special breath tests are used to test for lactose intolerance, or bacterial overgrowth of the small bowel. If these tests do not find the cause, other approaches may be needed, including x-rays or procedures, such as colonoscopy or sigmoidoscopy. Your primary care provider can order these tests or refer you to a specialist (a gastroenterologist). In many patients with chronic diarrhea, a specific, curable cause cannot be identified. These patients may have irritable bowel syndrome. (See "Patient education: Colonoscopy (Beyond the Basics)" and "Patient education: Flexible sigmoidoscopy (Beyond the Basics)".)

In some cases, your doctor or nurse will recommend a trial of treatment before more invasive tests (see 'Treatment trial' below).


Treatment of chronic diarrhea aims to eliminate the underlying cause (if the cause is known), firm up the bowel movements, and treat any diarrhea-related complications.

Treating the cause — The underlying cause of chronic diarrhea should be found and treated whenever possible. For example, infections may be treated with antibiotics. In people with Crohn disease or ulcerative colitis, long-term treatment and follow-up is needed.

In some cases, treatment may be as simple as eliminating a food or medicine.

For people with lactose intolerance, this may include foods or drinks that contain lactose (table 1).

Other ingredients that are known to cause diarrhea include sugar-free products made with sorbitol and foods made with fat replacements (eg, Olestra).

Certain medicines can also cause diarrhea (such as laxatives and antacids).

Treating diarrhea — In some people, the goal is simply to have less diarrhea. This approach is often used before testing, when the results of tests are normal or not helpful, or if diarrhea is caused by a chronic medical problem.

Diarrhea treatments include:

Bismuth (sold as Kaopectate, Pepto-Bismol)

Treatments that bulk the stools, such as a high-fiber diet or fiber supplement (see "Patient education: High-fiber diet (Beyond the Basics)")

Antidiarrhea medicines – Examples include loperamide (sold as Imodium, available without a prescription) or prescription medicines, such as diphenoxylate-atropine (Lomotil). If you take loperamide, be careful to never exceed the dose on the label unless specifically instructed by your doctor. Taking more than the recommended dose has led to serious heart problems in some people.

Octreotide, a prescription medicine that might be given to people with severe diarrhea

Treatment trial — Your doctor or nurse might recommend trying a treatment before further testing. This approach can help to narrow down the list of possible causes of your diarrhea.

Treatments that might be offered include:

A trial of antibiotics, for an infection

Stopping a medicine

Changing your diet, for a possible food allergy or problem absorbing nutrients (such as lactose intolerance)

Treating complications — Chronic or severe diarrhea can lead to potentially serious complications, including dehydration and malnutrition. While you are being evaluated, you should be sure to drink plenty of fluids. You are drinking enough fluids if your urine is a light yellow color.

If you are not able to drink enough fluids and you become dehydrated, you may be given fluids into a vein (IV) to replace the fluids and electrolytes (salts) lost in diarrhea. This will not cure your diarrhea, but it can prevent more serious complications.


Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Diarrhea in adolescents and adults (The Basics)
Patient education: Diarrhea in children (The Basics)
Patient education: Food poisoning (The Basics)
Patient education: High-fiber diet (The Basics)
Patient education: Microscopic colitis (The Basics)
Patient education: Campylobacter infection (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Irritable bowel syndrome (Beyond the Basics)
Patient education: Crohn disease (Beyond the Basics)
Patient education: Ulcerative colitis (Beyond the Basics)
Patient education: Food poisoning (foodborne illness) (Beyond the Basics)
Patient education: Celiac disease in adults (Beyond the Basics)
Patient education: Colonoscopy (Beyond the Basics)
Patient education: Flexible sigmoidoscopy (Beyond the Basics)
Patient education: High-fiber diet (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Approach to the adult with chronic diarrhea in resource-rich settings
Clinical features and diagnosis of malabsorption
Small intestinal bacterial overgrowth: Clinical manifestations and diagnosis
Clinical manifestations, diagnosis, and prognosis of ulcerative colitis in adults
Epidemiology, clinical manifestations, and diagnosis of cryptosporidiosis
Cyclospora infection
Definition, epidemiology, and risk factors in inflammatory bowel disease
Differential diagnosis of microbial foodborne disease
Eosinophilic gastroenteritis
Giardiasis: Epidemiology, clinical manifestations, and diagnosis
Small intestinal bacterial overgrowth: Etiology and pathogenesis
Evaluation of the HIV-infected patient with diarrhea
Epidemiology, clinical manifestations, and diagnosis of Cystoisospora (Isospora) infections
Lactose intolerance: Clinical manifestations, diagnosis, and management
Lymphocytic and collagenous colitis (microscopic colitis): Clinical manifestations, diagnosis, and management
Overview of the medical management of mild to moderate Crohn disease in adults
Management of severe ulcerative colitis in adults
Overview of the management of Crohn disease in children and adolescents
Treatment of irritable bowel syndrome in adults
Giardiasis: Treatment and prevention

The following organizations also provide reliable health information.

National Library of Medicine


National Institute of Diabetes and Digestive and Kidney Diseases



Literature review current through: Nov 2017. | This topic last updated: Wed Sep 07 00:00:00 GMT 2016.
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