How to Rehydrate after Diarrhea

Diarrhea is a common condition that usually goes away on its own after a few days. However, diarrhea may also have dangerous side effects, such as dehydration.

In this article we’ll explain how to avoid getting dehydrated when you have diarrhea and when to seek medical help. 

What Causes Diarrhea

Diarrhea is a very common condition characterized by loose and watery stool. It usually resolves without intervention within a few days.

Types of diarrhea 

Diarrhea can be classified under three categories: 

Acute diarrhea

Acute diarrhea is the most common type of diarrhea that lasts for up to two days. Its causes are often unknown and it doesn’t necessitate treatment.

Persistent diarrhea

Persistent diarrhea generally lasts for two to four weeks.

Chronic diarrhea

Chronic diarrhea persists for more than four weeks or occurs regularly over longer periods of time.

Causes of acute and persistent diarrhea

The most common causes of acute and persistent diarrhea are viral, bacterial, or parasitic infections, as well as taking certain medications.


  • Viral infections, such as viral gastroenteritis, are one of the main causes of acute diarrhea.
  • Bacterial infections. Bacteria like Campylobacter, Escherichia coli, Salmonella, and Shigella, can enter your body through contaminated food or water and cause diarrhea.

  • Parasitic infections. The most common parasites that can enter your body through food or water include Cryptosporidium enteritis, Entamoeba histolytica, and Giardia lamblia parasites.

Traveler’s diarrhea

Travelers’ diarrhea is a travel-related illness caused by eating food or drinking water contaminated with bacteria, viruses, or parasites. 

Side effects of medicines

Many medicines, such as antibiotics, antidepressants, antacids containing magnesium, and drugs used to treat cancer, may cause diarrhea. Diarrhea can also be a sign of a serious reaction to a medicine, particularly if it contains lithium (Carbolith, Lithane) or digoxin (Lanoxin).

Causes of chronic diarrhea

Chronic diarrhea may have many different causes, from infections and food allergies to abdominal surgeries.


Some infections from bacteria and parasites can lead to chronic diarrhea that requires medical treatment. What’s more, some people develop difficulties digesting carbohydrates or proteins after infection that may prolong diarrhea.

Food allergies and intolerances

Chronic diarrhea can be caused by food intolerances and allergies, such as:

  • Lactose intolerance
  • Fructose intolerance 
  • Intolerance to sugar alcohols like sorbitol, mannitol, and xylitol 
  • Allergies to milk, soy, cereal grains, eggs, and seafood.

Digestive tract problems

Some digestive tract problems may cause chronic diarrhea, for example:

  • Celiac disease
  • Crohn’s disease
  • Ulcerative colitis
  • Irritable bowel syndrome (IBL)
  • Small intestinal bacterial overgrowth.

Abdominal surgery

Some people develop chronic diarrhea after an operation on the appendix, gallbladder, large intestine, pancreas, lii\ver, small intestine, or spleen, and other abdominal surgeries.

Long-term use of medicines

Medicines taken over a long period of time, like drugs that treat heartburn and stomach ulcers, may cause chronic diarrhea. These medicines can change the normal gut flora, increasing the chances of infection with Clostridioides difficile, bacteria that cause chronic diarrhea.

Symptoms of Diarrhea

The main, and sometimes only, symptom of diarrhea is passing loose, watery stools three or more times a day. However, when you have diarrhea, you may also experience one or more of the following symptoms:

  • Abdominal pain
  • Cramping
  • Bloating
  • Bloody stools
  • Nausea
  • Vomiting
  • Fever and chills
  • Light-headedness and dizziness

The symptoms may vary depending on the severity of diarrhea and its cause. 

Can You Dehydrate from Diarrhea?

Prolonged diarrhea and vomiting can cause your body to lose more fluids than it takes in. As a result, your body won’t have enough fluids to function properly and you may become dehydrated.

Severe dehydration can cause urinary tract infections, seizures, kidney stones, and even kidney failure. Dehydration is especially dangerous in children and the elderly.

Although mild and moderate dehydration can usually be reversed by drinking more fluids, severe dehydration requires immediate medical treatment.

What Are Symptoms of Dehydration?

When you have diarrhea, you should watch for the following signs of dehydration:

  • Extreme thirst
  • Less urination than normal
  • Inability to sweat
  • Dark-colored urine
  • Dry skin
  • Cracked lips
  • Headache 
  • Fatigue
  • Light-headedness
  • Dizziness 
  • Poor concentration
  • Confusion 
  • Low blood pressure (severe dehydration)

You should keep in mind that by the time these symptoms appear, dehydration may be already well advanced. Here is when it may be necessary to seek medical attention. 

When to Seek Medical Help

Diarrhea that leads to severe dehydration can become dangerous. Diarrhea may also be an indication of a more serious problem.

You should seek medical help if you experience any of the following symptoms:

  • Signs of dehydration
  • Diarrhea that persists for more than 3 days
  • Persistent vomiting for more than 48 hours 
  • A fever above 102 ℉ accompanied by nausea and vomiting
  • Blood in diarrhea or vomit
  • Severe stomach pain that doesn’t go away
  • Inability to keep any fluids down
  • Confusion and inability to focus
  • Feeling lethargic or sluggish.

In addition, older adults, individuals who have a weakened immune system, and people with other health conditions should see a doctor right away.

If you’re experiencing severe dehydration, call 911 or contact your nearest emergency department. 

To avoid getting dehydrated when you have diarrhea, you should start replacing lost fluids as quickly as possible.

Preventing Dehydration When Suffering from Diarrhea

When you are sick with diarrhea or vomiting, you lose fluid rapidly. It is essential to take in as much water and other liquids as you can to replenish the lost fluids.

Drinking water

Drinking sufficient amounts of water throughout the day is vital for preventing dehydration when you’re suffering from diarrhea. You should have at least one cup of water after each loose bowel movement.

Oral rehydration solutions

Although water can hydrate you, it doesn’t replace the essential electrolytes, such as sodium, calcium, and potassium, that help move water through your body. Experts recommend drinking oral rehydration solutions like Pedialyte and DripDrop that can replace both lost body fluids and electrolytes. 

Sports drinks

Sports drinks such as Gatorade, Powerade, and Lucozade Sport, help maintain hydration after a bout of diarrhea. The sugar content in these drinks is often relatively high, but it enables your body to absorb the electrolytes more efficiently.

Coconut water

Coconut water is a great alternative to sports drinks. It is rich in potassium and electrolytes, while it contains fewer calories and less sodium than sports drinks.

Avoiding certain foods and drinks

There are some foods that you should avoid to prevent dehydration, including:

  • Coffee, tea, and other caffeinated and soft drinks
  • Artificial fruit juices
  • Foods with high salt content, such as cured meats, pickles, prawns, and soya sauce
  • High-protein foods

Try to eat foods rich in minerals, glucose, and water content, for example, lettuce, squash, apples, cottage cheese, and white bread. These foods will help your body stay hydrated and replace lost electrolytes.

IV therapy

When you have diarrhea, IV therapy is the fastest and most effective way to get all the fluids and nutrients you need, since they are injected directly into your bloodstream. In addition to hydration, intravenous treatment helps flush out toxins and boost your energy levels

Reset IV’s Basic Hydration Package is based on a solution of normal saline fluid, a hydrating mixture of water and sodium chloride. Optional add-ons include vitamins, minerals, antioxidants, or medication to help you feel great again regardless of your needs.