Diarrhea Causes: Infection, IBS, Colitis, &amp

Diarrhea Causes: Infection, IBS, Colitis, &amp


Chronic Diarrhea

Medically reviewed by Elaine K. Luo, MD on September 25, 2017 — Written by Valencia Higuera


Diarrhea is a digestive condition that causes loose or watery stools. Many people experience diarrhea at some point. These bouts are often acute and resolve in a couple of days with no complications. Other people, however, live with diarrhea that persists for more than two to four weeks . This is called chronic diarrhea.

Acute, or short-term, diarrhea usually isn’t serious. But chronic loose, watery stools can lead to problems if left untreated. So it’s important to understand the cause of this type of diarrhea and treat any underlying condition.

Symptoms of chronic diarrhea

The main symptom of chronic diarrhea is loose or watery stools that persist for weeks. These stools may or may not be accompanied by a sense of urgency. You may have other symptoms as well, such as:

  • abdominal cramps
  • bloating
  • nausea

Causes of chronic diarrhea

Chronic diarrhea is sometimes caused by an underlying medical condition. See your doctor if diarrhea doesn’t respond to at-home care.

During your appointment, your doctor may conduct a physical examination and ask about your symptoms. For example, how often do you have loose stools? Do you have any other symptoms? Is there a personal or family history of digestive problems? Based on your physical exam and your symptoms, your doctor may order a complete blood count or a stool sample to check for infections or inflammation.

Inflammatory conditions that can cause loose, watery stools include ulcerative colitis and Crohn’s disease . These conditions can also cause bloody stools and abdominal pain.

A stool sample, which examines feces, may reveal elevated white blood cells. This can be a sign of inflammation in your body or bacteria or parasites in your stool. The latter can also cause loose stools. This sample may also reveal fat in your stool, which can indicate chronic pancreatitis (damage to the pancreas from prolonged inflammation) or celiac disease.

Your diet can also play a role in chronic diarrhea. Certain ingredients speed up the rate of digestion, causing food to pass rapidly through the colon. Common culprits include milk and artificial sweeteners (sorbitol and fructose).

Other causes of chronic diarrhea may include:

  • medications — NSAIDs, antibiotics, antacids
  • diabetes
  • gluten insensitivity
  • alcohol abuse

If a blood test or a stool sample can’t identify the cause of diarrhea, your doctor may suggest an ultrasound or CT scan of your abdomen, but only if you have other symptoms like pain or bloody stools. These imaging tests will check your organs for problems. Your doctor may also recommend a colonoscopy to examine your bowels for abnormalities. This tool can diagnose problems with the lining of your intestines, pancreas, and colon.

Sometimes, the cause of chronic diarrhea is unknown. If diagnostic tests don’t reveal an abnormality, your doctor may attribute chronic diarrhea to irritable bowel syndrome (IBS) .

This condition affects the large intestines and causes a variety of symptoms like diarrhea, constipation, bloating, nausea, and abdominal pain. IBS can be chronic, but it doesn't damage the large intestines.

Treatment options for chronic diarrhea

Anti-diarrheal medications can relieve diarrhea, but these medications aren’t recommended as a long-term therapy.

Treatment for chronic diarrhea depends on the underlying cause. For example, if you’re diagnosed with a medical condition like ulcerative colitis, Crohn’s disease, pancreatitis, or celiac disease, your doctor will discuss treatment options with you and recommend the best course of action. Treatment might include prescription medications like an immunosuppressant or a corticosteroid.

Diarrhea may improve as your health improves.

Additional treatment options for chronic diarrhea include:

Lifestyle and diet

Keep a food journal to help determine whether diet is an underlying factor in chronic diarrhea. Record all your meals and snacks, and make a note of any worsening of symptoms.

After a few weeks, you may be able to identify possible trigger foods. If so, eliminate these foods from your diet to see if your symptoms improve. For example, diarrhea may stop or significantly improve after stopping your intake of gluten, artificial sweeteners, or dairy products. Or your condition may improve after removing certain vegetables, fruits, and beans from your diet.

Lifestyle changes to help resolve chronic diarrhea include:

  • avoiding caffeine and alcoholic beverages
  • eating low fiber foods
  • drinking clear fluids to prevent dehydration
  • controlling food portions to avoid overeating


If bacteria or a parasite causes chronic diarrhea, your doctor may prescribe an antibiotic. Prescription medications containing codeine may also provide relief because they increase the time it takes stools to pass through the digestive tract, resulting in bulkier stools. However, there’s the risk of addiction with these medications, so your doctor may not recommend codeine as a long-term therapy.

Over-the-counter medications such as bismuth ( Pepto-Bismol ) and loperamide ( Imodium ) also slow the transit of stool, but they should only be taken on a short-term basis. Talk to your doctor before using these medications to treat chronic diarrhea.

Home remedies and natural remedies

Chronic diarrhea may develop after taking a prescription medication such as an antibiotic. Talk to your doctor about alternative drugs. If one isn’t available, incorporate probiotics into your diet to restore stool bulk. These are available in yogurt and capsule form.

Fiber supplements are associated with relieving constipation. But certain fiber supplements can also relieve chronic diarrhea because of its water-holding effect. Taking psyllium ( Metamucil ) on a daily basis can produce bulkier stools and lessen or eliminate diarrhea caused by IBS or medication.

Preventing chronic diarrhea

Chronic diarrhea caused by an underlying medical condition isn’t always preventable. But you can prevent chronic diarrhea due to infection by taking steps to keep your food and water supply clean. For example:

  • Drink from a clean water source or filter your water.
  • Thoroughly clean meat before cooking.
  • Cook meat thoroughly.
  • Wash your hands after handling food.
  • Clean kitchen surfaces to prevent contamination.
  • Wash fruits and vegetables before consuming them.
  • Wash your hands after using the bathroom, changing a diaper, or attending to a sick person.

Complications of chronic diarrhea

Acute diarrhea can be harmless. But with chronic diarrhea, there’s the risk of dehydration due to loss of fluid. Dehydration is when your body doesn’t have enough water. This can be life-threatening, so drink plenty of fluids. This includes water, broth, and unsweetened and decaffeinated tea. Signs of dehydration include:

  • dark urine
  • excessive thirst
  • dizziness
  • fatigue
  • vomiting
  • fever

See a doctor if you show signs of dehydration.

Outlook for chronic diarrhea

The outlook for chronic diarrhea depends on the cause. If you’re able to treat an inflammatory bowel disorder, infection, or other digestive problem, your stools should gradually return to normal. If you don’t have a medical condition, keeping a food journal, watching your diet, and making lifestyle changes may also provide relief. The important thing is that you don’t ignore the problem. The sooner you speak with your doctor, the sooner you can get relief.

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Medically reviewed by Elaine K. Luo, MD on September 25, 2017 — Written by Valencia Higuera

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Understanding Diarrhea — the Basics

In this Article

In this Article

In this Article

  • What Is Diarrhea?
  • What Causes Diarrhea?
  • Other Medical Conditions
  • Medications and Other Substances

What Is Diarrhea?

Most people think of diarrhea as an illness during which they have more frequent, loose, watery stools.


Almost everyone has it at some point. In developing countries, where illnesses that cause diarrhea are common and where health care is less available, diarrhea is a major health concern because of its potential to cause dehydration.


Diarrhea that comes on suddenly and goes away over a couple of weeks is called “acute diarrhea.” Most people with this get better on their own.


Diarrhea that lasts more than 4 weeks is “chronic diarrhea.” You usually need to go to a doctor so he can find the cause and treat you for any complications.





What Causes Diarrhea?

Many different things can cause diarrhea.


Infections: You may get an infection from contact with someone else. You may get one after having contaminated food or water. If you eat something that was improperly cooked or contaminated after cooking, the infection is called food poisoning. Diarrhea, cramps, and vomiting are common with food poisoning. Children who attend day care and their families are more likely to get these infections.


People who travel to foreign countries get “traveler’s diarrhea,” usually after drinking bad water. Infectious diarrhea is a problem in developing countries, where it may be hard to keep waste water and sewage separate from water used to cook, drink, and bathe.


Medications: Many medicines can cause diarrhea. Some of the most common include:


  • Antacids with magnesium
  • Laxatives
  • Digitalis
  • Metformin
  • Some antibiotics
  • Chemotherapy drugs
  • Cholesterol-lowering agents
  • Lithium
  • Theophylline
  • Thyroid hormone
  • Colchicine


Too much caffeine or alcohol: You may need to cut back on one or both to see if that does the trick.


Toxins such as insecticides, psychedelic mushrooms, and arsenic: They cause diarrhea, too.


A digestive problem: This could be lactose intolerance, celiac disease, or pancreatic problems.


Surgery to remove part of your small intestine: After that procedure, you may not be able to absorb everything you eat. Your doctor may call it short-bowel syndrome.


Removal of your gallbladder: The increase of bile in your colon from this procedure may result in watery stools.



Hormonal disorders: This includes overactive thyroid disease, diabetes, adrenal disease, and Zollinger-Ellison syndrome.


Certain rare tumors: Things like a carcinoid tumor and pheochromocytoma can bring diarrhea on.


Inflammatory bowel disease: Ulcerative colitis, Crohn’s disease, or microscopic colitis will give you diarrhea during flare-ups.


Irritable bowel syndrome (IBS): This may cause both diarrhea and constipation.


Ischemic bowel disease: This can be caused by blocked arteries. Symptoms might include abdominal pain with bloody diarrhea.


Radiation therapy for cancer: It can damage the intestine and cause diarrhea.

Other Medical Conditions

A number of noninfectious medical conditions may cause diarrhea. These include:


  • Inability to digest certain foods, including lactose intolerance (difficulty digesting sugar found in dairy products); celiac disease (an immune reaction to consuming gluten, a protein found in wheat, barley, and rye); and pancreatic problems, such as those caused by cystic fibrosis, which interfere with production of important digestive substances.
  • Surgery to remove part of your small intestine. A shortened small intestine may be unable to absorb all the substances you eat. This is referred to as short-bowel syndrome.
  • Surgical removal of the gallbladder. An increase in bile in the colon may result in watery stools.
  • Certain diseases of the endocrine (hormonal) system, including overactive thyroid disease, diabetes, adrenal disease, and Zollinger-Ellison syndrome
  • Certain rare tumors (including carcinoid tumor and pheochromocytoma) that produce diarrhea-causing substances (hormones)
  • Inflammation in the intestinal tract, which can result in chronic diarrhea. If you have inflammatory bowel disease (such as ulcerative colitis, Crohn’s disease, or microscopic colitis), you will have regular bouts of diarrhea during a flare-up of your disease.
  • Irritable bowel syndrome, which may cause alternating bouts of diarrhea and constipation
  • Ischemic bowel disease, which can be caused by blocked arteries. Symptoms might include abdominal pain with bloody diarrhea.



Medications and Other Substances

Many medications can cause diarrhea. Some of the most common include antacids containing magnesium, laxatives, digitalis, diuretics, a number of antibiotics, chemotherapy drugs, cholesterol-lowering agents, lithium, theophylline, thyroid hormone, and colchicine.


Radiation therapy for prostate cancer or cancers in the abdomen can damage the intestine and cause diarrhea.


Toxins such as insecticides, psychedelic mushrooms, and arsenic can cause diarrhea, and overuse of caffeine or alcohol may contribute to diarrhea.


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further reading

  • Slideshow: Worst Foods for Digestion
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  • Diarrhea: Triggers and Treatments
  • Diarrhea Symptoms: When Are They Something More Serious?
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  • Avoiding Diarrhea When Traveling
  • Diarrhea Topics

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