Key takeaways

  • Explosive diarrhea is characterized by strong bowel contractions, increased volume in the rectum, and often accompanied by significant gas.
  • Common causes include bacterial, viral, and parasitic infections, bowel diseases, certain medications, and food allergies or intolerances.
  • While usually short-lived, severe diarrhea can lead to complications like dehydration, chronic diarrhea, and, in rare cases, hemolytic uremic syndrome, necessitating medical attention.

Diarrhea is when you pass three or more watery stools in 1 day.

With explosive diarrhea, the contractions of your bowels that help you pass feces become stronger and more forceful. Your rectum fills with more volume than it can contain.

Often, large amounts of gas accompany severe diarrhea due to the same causes as the causes of the diarrhea, which can include infection and poor absorption of food by your body. This increases the ejection and loudness of the bowel movement.

Approximately 75% of your stool is made of water. The other 25% is a combination of:

As feces travel through your digestive system, fluids and electrolytes are added to their content. Normally, your large intestine absorbs the excess fluid.

When you have diarrhea, though, digestion speeds up. Either the large intestine isn’t able to absorb the rush of fluid or more than the usual amount of fluids and electrolytes are secreted during digestion.

Diarrhea is a symptom that occurs with a number of conditions. The most common causes for severe diarrhea include:

Bacterial and viral infection

Bacteria that cause diarrhea-producing infections include salmonella and E. coli. Contaminated food and fluids are common sources of bacterial infections.

Rotavirus, norovirus, and other kinds of viral gastroenteritis, commonly referred to as “stomach flu,” are among the viruses that can cause explosive diarrhea.

Anyone can get these viruses. But they’re especially common among school-age children. And they’re common in hospitals, nursing homes, and on cruise ships.

Parasitic infection

Parasites like Giardia lamblia and cryptosporidium can cause severe diarrhea, particularly in people with weakened immune systems. As with viral and bacterial causes, these parasites are spread when there’s contact between feces and the mouth.

These parasites are found in contaminated drinking water, bodies of water like lakes and ponds, and food. Day care centers are particularly vulnerable to outbreaks of parasites.

Diseases of the bowel

Diarrhea is a common symptom for people who have:

Medications

Many medications can cause diarrhea. Antibiotics, certain medications used to treat heartburn and acid reflux, and chemotherapy drugs are frequent culprits.

Allergies or food intolerance

Diarrhea often occurs when you are allergic to, or have an intolerance of, certain foods, like the lactose found in dairy products.

Explosive diarrhea is usually short-lived. But there are complications that require medical care. These include:

Dehydration

Loss of fluids from diarrhea can cause dehydration. This is a particular concern in infants and children, older adults, and people with compromised immune systems.

An infant can become highly susceptible to severe dehydration within 24 hours.

Chronic diarrhea

If you have diarrhea for more than 4 weeks, it’s considered chronic. A doctor will advise testing to determine the cause of the condition so it can be treated.

Hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a rare complication of E. coli infections. It occurs most often in children, though adults, particularly older adults, can get it, too.

HUS can cause life-threatening kidney failure if not treated promptly. With treatment, most people fully recover from the condition.

Symptoms of HUS include:

Diarrhea is common, but some people are at greater risk, such as:

  • children and adults who are exposed to feces, especially those who are involved in changing diapers
  • people who travel to developing countries, particularly in tropical regions
  • people taking certain medications, including antibiotics and medications used to treat heartburn
  • people who have bowel disease

Diarrhea typically clears up within a few days without treatment. But you should see a medical professional if you experience:

  • diarrhea lasting longer than 2 days (or 24 hours in a child)
  • symptoms of dehydration, including excessive thirst, dry mouth, reduced urination, or dizziness
  • blood or pus in your stool, or stool that’s black in color
  • a fever of 101.5 °F (38.6 °C) or greater in an adult, or 100.4 °F (38 °C) or higher in a child
  • severe abdominal or rectal pain
  • diarrhea at night

If your primary care physician is not available, consider visiting a walk-in clinic or urgent care center.

Your doctor will ask questions about your symptoms, including:

  • how long you’ve had diarrhea
  • if your stools are black and tarry, or contain blood or pus
  • other symptoms you’re experiencing
  • medications you’re taking

The doctor will also ask about any clues you may have as to the cause of the diarrhea. Clues could be a food or fluid you suspect may have something to do with your illness, travel to a developing country, or a day of swimming in a lake.

After providing these details, a doctor may:

In many cases, diarrhea treatment will involve managing your symptoms while you wait for the diarrhea to pass. The primary treatment for severe diarrhea is to replace fluids and electrolytes. Electrolytes are the minerals in your body fluid that conduct the electricity your body needs to function.

Drink more fluids, like water, and juice, or broths. Oral hydration solutions, such as Pedialyte, are formulated specifically for infants and children, and contain important electrolytes. These solutions are also available for adults.

You can use over-the-counter (OTC) anti-diarrheal medications if your stool isn’t black or bloody, and you don’t have a fever. These symptoms indicate you may have a bacterial infection or parasites, which can be made worse by anti-diarrheal medications.

OTC medications should not be given to children younger than 2 unless approved by a doctor. If your infection is bacterial, your doctor may prescribe antibiotics.

Additionally, OTC medications should not be used if Shiga toxin-producing Escherichia coli (STEC) is suspected as it can lead to hemolytic uremic syndrome.

It’s difficult to completely avoid getting severe diarrhea. But there are steps you can take to protect yourself and your family.

Sanitation is crucial. Wash your hands with soap and warm water, especially before handling food, after using the toilet, or after changing a diaper.

If you’re traveling to an area where water purity is a concern, stick with bottled water for drinking and brushing your teeth. And peel raw fruit or vegetables before eating.

Next steps

If you do get explosive diarrhea, there are some steps you can take to make yourself more comfortable and improve your outlook for a speedy recovery:

  • Keep sipping water and other fluids. Stick to a diet of clear liquids for up to 2 days until the diarrhea stops.
  • Avoid sugary fruit juices, caffeine, carbonated drinks, dairy products, and food that’s greasy, overly sweet, or high in fiber.
  • There’s one exception to avoiding dairy products: Yogurt with live, active cultures may help curb diarrhea.
  • Eat a diet of bland, soft foods for up to 2 days. Starchy foods like cereal, rice, potatoes, and soups made without milk are usually recommended.

In most people, diarrhea will clear up without requiring treatment or a trip to the doctor. Sometimes, though, you may need medical treatment, especially if your diarrhea leads to dehydration.

Diarrhea is a symptom rather than a condition. The underlying cause of diarrhea varies greatly. If you have symptoms of complications or experience chronic diarrhea, it’s best to work with a doctor to determine the cause so that it can be treated.