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Diarrhea: Types, Causes, & Treatment

Introduction and Summary

If you have ever experienced making frequent trips to the bathroom, you are not alone. Diarrhea is not pleasant, but it is something most people experience at one point or another. In fact, it is one of the most commonly reported symptoms.

On average, American adults experience one bout of acute diarrhea each year, while young children and babies get it more frequently. Fortunately, diarrhea is typically short-lived and most cases resolve on their own.

In this article I’ll explore:

What Is Diarrhea?

Diarrhea is defined as frequent loose, watery bowel movements. Normally, stool is 60-90% water. Diarrhea occurs when not enough water is removed from the stool, causing it to become loose and poorly formed.

These frequent bowel movements can be caused by a variety of different conditions from temporary viral and bacterial infections such as food poisoning, irritable bowel syndrome (IBS), to more serious conditions like inflammatory bowel disease (IBD) and gastrointestinal bleeding.

Acute cases of diarrhea last up to two weeks, while chronic or persistent diarrhea can last between two and four weeks and may be a sign of a more serious problem. It is important to pay attention to how long your diarrhea lasts, what it looks like, and if you are experiencing other symptoms.

Types of Diarrhea

While some characteristics of diarrhea are consistent, others such as length of a case and color, can vary and are important factors to pay attention to.

Types of diarrhea include:

  • Acute diarrhea: Diarrhea that lasts for less than two weeks. Most cases of acute, watery diarrhea are caused by viruses or bacteria (such is the case for the common travelers’ diarrhea). Most cases of acute diarrhea will approve on their own within two to three days.
  • Chronic diarrhea: Diarrhea that lasts longer than four weeks (also known as persistent diarrhea). This type of diarrhea may be a result of a more serious condition and should be brought to the attention of your doctor.

Diarrhea can also be classified by look or color:

  • Watery diarrhea: Liquid stool common in both acute and chronic cases of diarrhea.
  • Bloody diarrhea: A potentially serious condition where blood mixes in with loose, watery stools. Bloody diarrhea may be a sign of gastrointestinal bleeding due to injury or disease. Small amounts of blood may also be due to irritation of the rectal tissue or hemorrhoids.
  • Black diarrhea: Could indicate bleeding from a location somewhere in the higher portion of the digestive tract. Other potential causes of black diarrhea include taking iron supplements or bismuth subsalicylate (Pepto-Bismol), or consuming foods or liquids that are blue or black in color.
  • Yellow diarrhea: Could indicate an underlying disorder in the liver or gallbladder. This is normal in infants.
  • Green diarrhea: May be seen after eating leafy greens or foods with artificial green coloring. This can also be a normal color in infants and toddlers.

Other Symptoms of Diarrhea

In addition to frequent loose, watery bowel movements, diarrhea may be accompanied by other symptoms. Depending on the cause, it’s common to experience one or more of the following:

What Causes Diarrhea?

There are many different causes of diarrhea which vary from common to complex. Typically, more common causes lead to acute diarrhea, while more severe may lead to chronic diarrhea. Though chronic diarrhea may also have a less serious cause like a food intolerance. It’s helpful to keep track of recent lifestyle changes that could help you answer the question, “why do I have diarrhea?”

Causes of acute diarrhea

Acute diarrhea is commonly caused by viruses. The most common one in children is rotavirus and in adults is norovirus. If you are experiencing consistent diarrhea for short periods of time, it could be due to one of the following issues:

  • A viral infection
  • A bacterial infection
  • A parasitic infection
  • Food intolerance
  • Food allergy
  • Food poisoning
  • Adverse reaction to a medication
  • Certain foods (such as milk and artificial sweeteners)

Causes of chronic diarrhea

Chronic diarrhea may be a symptom of a more serious or chronic condition such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). Frequent and severe diarrhea could be a sign of these associated conditions:

  • Inflammatory bowel disease (IBD)
  • Irritable bowel syndrome (IBS)
  • Infection
  • Radiation therapy
  • Adverse reaction to a medication
  • Diabetes
  • Gluten insensitivity (celiac disease)
  • Lactose intolerance or other food intolerance
  • Alcohol abuse
  • HIV or other immunodeficiency
  • Overgrowth in harmful colon bacteria due to recent antibiotic use (c. difficile colitis)

Diarrhea during pregnancy

It is relatively common for women to experience diarrhea during pregnancy—especially in the third trimester. This can be attributed to shifting hormones, food sensitivities, prenatal vitamins, and added stress. It’s important to stay hydrated and discuss with your obstetrician if it is persistent or you are having multiple episodes per day or severe abdominal pain or cramping.

What to Watch For and Risk Factors

There are several lifestyle risk factors that can increase your chance of experiencing diarrhea—these include changes to your diet, personal hygiene, and food handling.

  • Dietary changes: A mostly liquid diet, suddenly increasing fiber intake, or eating spicy or fatty foods may lead to diarrhea. “Detox” teas or weight loss teas or supplements may cause diarrhea as well.
  • Personal hygiene: Bacteria, viruses, and parasites that cause diarrhea are spread by contact with contaminated surfaces, food, and water. A lack of personal hygiene, especially hand washing, can expose you to these infectious agents in a variety of ways.
  • Improper food handling: To avoid food poisoning, it’s important to separate raw meat, seafood, poultry and eggs from other food, use a food thermometer to ensure they are cooked properly, and thoroughly clean any surface that has come in contact with raw food.

How to Get Rid of Diarrhea

There is never a convenient time to get diarrhea. In fact, it often strikes at the worst times—during a much-anticipated vacation or event. The good news is, most cases of acute diarrhea improve on their own within 1-2 weeks. Some remedies that may be helpful include:

  • Drink plenty of water or electrolyte replacement beverages.
  • Take an over-the-counter diarrhea medicine (such as loperamide) to help slow down the movement of the gut.
  • Try a probiotic supplement—specifically one that contains lactobacillus.
  • Temporarily modify your diet to consume more low-fiber, bland foods and avoid fried, greasy, and high-fiber foods.
  • Cooked carrots, applesauce, and bananas can all help slow down diarrhea.

For more serious cases, you may need to talk to a doctor. Your doctor will perform an examination to decide what tests or treatments are needed to help get rid of your diarrhea and determine if it could be the result of an underlying condition.

How to Prevent Diarrhea

Though it is hard to completely prevent diarrhea, the best defense against diarrhea is to practice good hygiene, handle food safely, and wash your hands frequently.

In your daily life, you can proactively help yourself prevent diarrhea by practicing the following:

  • Wash your hands with soap and water frequently throughout the day.
  • Properly disinfect all surfaces that come into contact with raw foods.
  • Be sure that all foods you eat are thoroughly cooked and served hot.
  • Avoid raw or undercooked meat or seafood.

In addition to the tips above, you should take the following steps when traveling to certain countries:

  • Drink only bottled water, even for tooth brushing, unless you can confirm the water comes from a trusted source. Make sure the seal of the water bottles is intact.
  • Avoid eating food from unknown vendors.
  • Avoid ice made with tap water.
  • Eat only those fruits or vegetables that are cooked or can be peeled.
  • Obtain proper vaccinations prior to travel, if indicated for that region.

When to See a Doctor

Most episodes of acute diarrhea resolve on their own without any treatment. You should see a doctor if you experience the following symptoms:

  • Bloody diarrhea
  • Signs of dehydration
  • Severe abdominal pain
  • Inability tolerate oral fluids
  • Recent travel to a high-risk area, recent camping, or exposure to undercooked meat or unpasteurized dairy
  • If you have recently been on antibiotics
  • Diarrhea in an infant that lasts more than 24 hours

What to expect when you see a doctor

Your doctor will ask questions about your symptoms and medical history. Even though it might not be pleasant, try to give as much detail about your bowel movements and other symptoms as possible.

The doctor will want to know:

  • If there’s blood or mucus in your diarrhea
  • How watery it is and how many episodes per day
  • How long you’ve had it
  • If anyone else in your household is sick
  • If you have abdominal pain
  • If you have a fever
  • If you feel dizzy or confused
  • If you have traveled anywhere recently or been camping
  • If you are taking antibiotics or have recently taken antibiotics
  • Your general diet

The doctor will then do a physical examination to carefully feel your abdomen and may perform a rectal exam to check for bleeding, fissures, or hemorrhoids. This will help identify the cause of diarrhea or determine what tests need to be done.

Tests are not always needed for diarrhea, but some tests your doctor may order to determine the cause of diarrhea include:

  • A stool culture to check for viruses, bacteria, or parasites
  • Food elimination to determine whether a food intolerance or allergy is the cause
  • Blood testing for signs of celiac disease or inflammatory bowel disease
  • Breath testing for lactose intolerance
  • Imaging tests to check for inflammation or other abnormalities in the intestine
  • A colonoscopy to check the entire colon for signs of intestinal disease
  • A sigmoidoscopy to check the rectum and lower colon for signs of intestinal disease

How K Health Can Help

Diarrhea is unpleasant but there are many treatments that can help you recover quickly. Did you know you can get affordable primary care with the K Health app? Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Dr. Sarah Malka, MD

Dr. Sarah Malka is a board certified emergency medicine physician with K Health. She completed her residency at Harvard Medical School.

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