1 Diarrhea Summary

Diarrhea is a condition where you experience increased frequency of bowel movements or increased looseness of stool, or both. You can consider someone to have diarrhea if he or she has passed out three or more loose or watery stools within 24 hours.

Diarrhea can be a classic symptom of an underlying medical condition or infection. In some cases, diarrhea is caused by intense stress or anxiety. The presence of infectious bacteria in consumed food or drink can trigger diarrhea.

Diarrhea is actually a response to flush out harmful pathogens in the digestive tract. However, diarrhea can also occur if you are emotionally stressed since the digestive tract is connected to the brain via the vagus nerve. 

Diarrhea happens when the intestines speed up the passage of digested food. The digested food inside the intestines is watery, and the intestinal walls normally absorb water and nutrients from it as it passes through the digestive tract. So if food passes too quickly, the water is left unabsorbed, causing the stool to become loose and watery.

Because the affected feces are semisolid or full of liquids, it passes very quickly so you tend to experience a sense of discomfort and urgency. The valves in the anus, which are designed to hold solid stool, cannot withhold liquid stool that sometimes causes incontinence or leaks.

Diarrhea can be dangerous because it causes dehydration. Severe dehydration can greatly reduce the volume of the blood that causes the patient to go into shock. Also, diarrhea can result in loss of important electrolytes in the body such as sodium, potassium, calcium, magnesium and phosphate. Electrolytes are needed for proper functioning of cells, especially for vital functions such as heartbeat rhythm, muscle contraction, and pH level (acidity or alkalinity) of the blood. Diarrhea prevents intestines from absorbing minerals from food to be used as electrolytes.

In many cases, diarrhea is self-limiting and stops on its own without treatment. Depending on the individual’s condition, treatments, and the cause, diarrhea can be either harmless or serious. Diarrhea that lasts for at least a day or two is usually serious and requires immediate treatment. Children and elderly are more sensitive to dehydration caused by diarrhea, and so require urgent treatment.

However, if it continues to worsen and left untreated, diarrhea can be fatal. In third-world countries where health facilities are inadequate and populations have little access to healthcare personnel, diarrhea is among the most common cause of death. In fact, more people die from diarrhea that from malaria, AIDS, or measles.

Diarrhea is not only dangerous, as it can also be a source of inconvenience or even embarrassment. Your daily activities are affected if you have diarrhea. You cannot perform or finish tasks at home, work, or school if you have to frequently go to the bathroom and spend lots of time sitting in the toilet. The worse times to have diarrhea is when you are at school, while travelling (especially in the airplane, or being in a place with inadequate toilet facilities).
Treatments for diarrhea can be simple or complex, depending on the underlying cause and your overall health when it occurred.

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2 Causes

Diarrhea has several causes. Diarrhea is often a consequence of infection of the digestive tract. Sometimes, diarrhea can be caused by certain foods, taking certain medicines, or it can happen to individuals who are stressed.

Microorganisms in food or drink

In many cases, diarrhea is caused by the presence of infectious microorganisms in ingested food or drink. Virtually any bacteria, viruses, fungi, yeasts, or mold can cause diarrhea. Note that the immune system has a significant presence in the digestive tract. If any amount of microorganism triggers immune system activity in the digestive tract, diarrhea may occur.

Microorganisms in food or drink cause traveller’s diarrhea, and wilderness-acquired diarrhea. These types of diarrhea often resolve in few days with treatment.

Eating certain foods

Certain foods cause indigestion that can give you diarrhea. Depending on the individual or type of food eaten, diarrhea caused by indigestion can be mild or severe.

Diarrhea caused by food or indigestion is self-limiting in most cases. Here is the list of foods that often cause diarrhea:

  • Oily or deep-fried food items
  • Citrus fruits like oranges, grapefruit, tangerines, or clementines
  • Foods very high in sugar like maple syrup, honey, or waffle syrup
  • Artificial sugar or sugar substitutes (especially sorbitol), especially when taken in large quantities
  • Fiber in food, such as whole grains and vegetables, when eaten in large quantities
  • Beans
  • Cabbage and broccoli
  • Fructose, which is often found in sodas, fruit juices, and pastries
  • Spicy foods
  • Milk and dairy products
  • Peppermint
  • Chocolate
  • Coffee


Certain drugs can trigger diarrhea. In these cases, diarrhea is often mild and usually clears up without treatment. Diarrhea caused by medications can be mild or severe. In certain cases, like diarrhea caused by antibiotics, require treatment by the doctor.

Here is the list of medicines that often cause diarrhea:

  • Almost all antibiotics, especially cephalosporins like Cefixime and Cefpodoxime, and penicillins such as Amoxicillin and Ampicillin.
  • Medications used for depression (antidepressants), especially atypical antidepressants like Bupropion, Mirtazapine, Nefazodone, Trazodone, and Vortioxetine, and older ones like Amitryptiline, and Nortryptiline.
  • Antacids, especially ones that only contain magnesium, such as Milk of Magnesia
  • Proton-pump inhibitor drugs, which are used to reduce acids in the stomach, such as Omeprazole, Lansoprazole, Esomeprazole, and Pantoprazole.
  • Chemotherapy agents or medicines used to treat cancer, which often causes diarrhea as a side effect. A lot of chemotherapy drugs cause diarrhea.

Medical conditions

Diarrhea can also be caused by medical conditions or diseases. Conditions like cholera, dysentery, and Crohn’s disease often causes severe diarrhea that requires urgent treatment. In these cases, resolving the underlying cause often stops diarrhea.

Here are the diseases that feature diarrhea as a symptom:

Result of medical procedures

Some medical procedures cause diarrhea, such as:

  • Removal of part of the stomach or intestine
  • Surgical bypass of the intestine
  • Ingestion of castor oil for treating constipation
  • Side effect of contrast agents used to visualize the insides of the digestive tract, such as barium

3 Diagnosis and Treatment

You may experience diarrhea from time to time. Many cases of diarrhea disappear with little or no treatment. However, diarrhea needs urgent treatment if it happens to babies, small children, the elderly, pregnant patients, and those who are already sick or weak.


Doctors diagnose diarrhea by examining symptoms. He or she may also conduct an interview and ask questions about the following:

  • Foods recently eaten, especially culprit items like raw seafood, ground beef, sprouts, and wholesale salads at supermarkets
  • Drinking from questionable sources of water
  • Staying in regions where food and water sources are questionable
  • Recent travel, going into the wilderness, travel abroad or on a cruise ship
  • Medications taken
  • Medical history or presence of other medical conditions

The doctor may order the following tests to determine the cause of diarrhea:

  • Blood tests to determine blood volume or check for signs of infection
  • Stool exam, which examines your stool to determine presence of disease-causing pathogens or blood
  • X-rays of the abdomen to determine presence of parasite infestation
  • Intestinal biopsy, or getting a sample of intestinal tissue through a short operation, which is indicated for cases of diarrhea whose cause is unknown

Home remedies and first aid for diarrhea

There are remedies or first-aid to treat diarrhea at home. In some cases, early intervention for diarrhea can be lifesaving if it occurs to your child or elderly.

The goal for treating diarrhea is focused on replacing lost fluids to prevent dehydration. Give the patient clear fluids to drink often. You can give water, fruit juices, soda, sports drinks, and clear broth. Alternatively, you can give a prepared oral re-hydration solution such as Pedialyte or Ceralyte. You can also make your own oral rehydration solution by dissolving 6 teaspoons sugar and 1/2 teaspoon of salt in one liter of clean water. Make the patient sip liquids or oral re-hydration solution often, especially after a bout of diarrhea.

If the patient or the child is unable to eat or drink, you need to call the doctor. This applies to children, adults, and elderly patients.

Hospital treatment for diarrhea

Hospitalization is necessary for severe and prolonged diarrhea (e.g. diarrhea that lasted 2 days), or if weakness or signs dehydration is present.

Once in the hospital, the first goal is to re-hydrate the patient. Intravenous fluids are usually given to increase blood volume and prevent the patient from progressing into shock. Lab tests are then performed to determine the cause of diarrhea or for the presence of other problems.

The ultimate cause of diarrhea is addressed after the patient has been stabilized. Diarrhea caused by viral infections, such as rotavirus or norovirus, often resolves in less than a week and only supportive measures (fluid and electrolyte replacement, rest) are needed. For bacterial infections, the doctor may prescribe a course of antibiotics to treat the infection. If the cause of diarrhea is malabsorption, the offending substance (dairy, lactose, fatty food) is removed from the diet.

Anti-diarrheal drugs such as Attapulgite and Loperamide is not routinely used to treat diarrhea and is not recommended as home treatment. Diarrhea is a way for the body to flush out infectious microorganism and toxins out of the digestive tract. Taking anti-diarrheal drugs stops flushing action that allows these offending germs to stay inside the body.


Taking oral rehydration solution, which is cheap and available as over-the-counter, remains the best and most cost-effective treatment for diarrhea. Aside from taking adequate fluids, you need to rest whenever you have diarrhea.
Avoid milk or dairy, caffeine, apple juice, or alcohol, which can worsen diarrhea.

You can resume eating once diarrhea has subsided. Start with soft and bland foods such as:

  • Steamed rice
  • Plain porridge
  • Boiled potatoes
  • Plain toast
  • Crackers

You can return gradually to a normal diet once you tolerate it.

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