Acute diarrhea is something nearly everyone has experienced at one time or another. The loose, watery stools and abdominal cramps that characterize diarrhea usually last a couple of days. Diarrhea often means more-frequent trips to the toilet and a greater volume of stool.

What is it?

  • Acute diarrhoea is something nearly everyone has experienced at one time or another. The loose, watery stools and abdominal cramps that characterize diarrhoea usually last a couple of days. Diarrhoea often means more-frequent trips to the toilet and a greater volume of stool.
  • By definition, chronic diarrhoea lasts much longer than does acute diarrhoea, generally longer than four weeks. It can be a sign of a serious disorder, such as inflammatory bowel disease, or a less serious condition, such as irritable bowel syndrome.
  • Diarrhoea may cause a loss of significant amounts of water and salts. Most cases of diarrhoea clear on their own without treatment.
But see your doctor if diarrhoea persists, if you become dehydrated or if you pass blood in your stool.

Symptoms

Signs and symptoms associated with diarrhea may include:

  • Frequent, loose, watery stools
  • Abdominal cramps
  • Abdominal pain
  • Fever
  • Blood in the stool
  • Bloating

In addition, other signs and symptoms such as nausea and vomiting may precede diarrhea that's caused by, for example, an infection. Bacterial or parasitic infections sometimes cause bloody stools, and fever may accompany these infections as well.

Causes

Normally, the food you eat remains in liquid form during most of the digestive process. When the unabsorbed food residue passes through your colon, most of the fluids are absorbed and what remains is a semisolid stool.

In diarrhoea, the food and fluids you ingest pass too quickly or in too large an amount — or both — through your colon. The fluids aren't sufficiently absorbed, and the result is a watery bowel movement. In addition, the lining of your colon may be inflamed or diseased, making it less able to absorb fluids.

The most common causes of diarrhea include:

  • Viruses. Common viruses that cause diarrhoea are Norwalk virus, cytomegalovirus, viral hepatitis and the herpes simplex virus. Rotavirus is the most common cause of acute childhood diarrhea. Viral diarrhoea spreads easily.
  • Bacteria and parasites. Contaminated food or water can transmit bacteria and parasites to your body. Parasites such as Giardia lamblia and cryptosporidium can cause diarrhoea. Common bacterial causes of diarrhoea include campylobacter, salmonella, shigella and Escherichia coli. Diarrhoea caused by bacteria and parasites can be common when traveling in developing countries, and is often called traveler's diarrhea.
  • Medications. Many medications can cause diarrhoea. The most common are antibiotics. Antibiotics destroy both good and bad bacteria, which can disturb the natural balance of bacteria in your intestines. This disturbance sometimes leads to an infection with bacteria called Clostridium difficile, which can also cause diarrhoea.

Other causes

  • Lactose. A sugar found in milk and milk products, lactose is a common cause of diarrhoea in some people.
  • Fructose. Fructose, a sugar found in many fruits, is a common cause of diarrhea, especially in children.
  • Artificial sweeteners. Sorbitol and mannitol, artificial sweeteners found in chewing gum and other sugar-free products, can cause diarrhea in some otherwise healthy people.
  • Surgery. Some people may experience diarrhoea after undergoing abdominal surgery or gallbladder removal surgery.
  • Other digestive disorders. Chronic diarrhea has a number of other causes, such as Crohn's disease, ulcerative colitis, celiac disease and irritable bowel syndrome.

Diagnosis

If you have diarrhea that requires medical attention, your doctor will ask about your symptoms and will want to determine if you're dehydrated. Tell your doctor about any medications you're taking, including over-the-counter medications — they may have caused the diarrhea.

Your doctor may examine your abdomen to determine the location of your pain, may listen to your abdomen with a stethoscope and may perform a rectal exam. Your doctor may suggest blood or stool tests to check for signs of infection or other abnormalities.

Treatments and drugs

Most cases of diarrhea clear on their own within a couple of days without treatment. If you've tried lifestyle changes and home remedies for diarrhea without success, your doctor may recommend medications or other treatments.

Antibiotics

Antibiotics may help treat diarrhea caused by bacteria or parasites. If a virus is causing your diarrhea, antibiotics won't help.

Treatment to replace fluids

Your doctor likely will advise you to take steps to replace the fluids and salts lost during diarrhea. For most people, replacing fluids means drinking water, juice or broth. If drinking liquids upsets your stomach or causes diarrhea, your doctor may recommend getting fluids through a vein in your arm (intravenously).

Water is a good way to replace fluids, but it doesn't contain the salts and electrolytes — minerals such as sodium and potassium — you need in order to maintain the electric currents that keep your heart beating. Disruption of your body's fluid and mineral levels creates an electrolyte imbalance that can be serious. You can help maintain your electrolyte levels by drinking fruit juices for potassium or eating soups for sodium.

Adjusting medications you're taking

If your doctor determines that an antibiotic medication caused your diarrhea, your doctor may modify your treatment plan by lowering your dose or switching to another medication.

Treating underlying conditions

If your diarrhoea is caused by a more serious disease or condition, such as inflammatory bowel disease, your doctor will work to control that condition. You may be referred to a specialist, such as a gastroenterologist, who can help devise a treatment plan for you. 

Lifestyle remedies

Most diarrhea clears up on its own within a few days. To help you cope with your signs and symptoms until they go away, try to:

Drink plenty of clear liquids, including water, broths and juices every day. But, avoid apple and pear juices until you feel better because they can make your diarrhea worse. Avoid caffeine and alcohol. Eating gelatin also may help.

Add semisolid and low-fiber foods gradually as your bowel movements return to normal. Try soda crackers, toast, eggs, rice or chicken.
Avoid certain foods such as dairy products, fatty foods, high-fiber foods or highly seasoned foods for a few days.

Ask about anti-diarrheal medications. Over-the-counter (OTC) anti-diarrheal medications, such loperamide (Imodium), may help reduce the number of watery bowel movements you experience. Certain infections — bacterial and parasitic — may be made worse by these OTC medications because they prevent your body from getting rid of what's causing the diarrhea. Also, these drugs aren't always safe for children. Check with your doctor before taking these medications or giving these medications to a child.

Alternative medicine

Some research suggests that probiotics — foods and supplements containing beneficial bacteria — may help treat diarrhea, particularly viral diarrhea in children. Helpful bacteria live in your digestive tract, where they help digest your food and protect you from harmful bacteria. Probiotics contain strains of living bacteria that are similar to the ones normally found in your digestive system.

Probiotic foods, such as yogurt, cheese, miso and tempeh, are generally safe to eat and may help. Side effects of probiotics might include gas and bloating.

Prevention

Preventing viral diarrhea

Wash your hands frequently to prevent the spread of viral diarrhea. To ensure you or your child is washing your hands thoroughly, always:

  • Wash frequently. Wash your hands after preparing food, handling uncooked meat, using the toilet, changing diapers, sneezing, coughing and blowing your nose.
  • Lather with soap for at least 20 seconds. After putting soap on your hands, rub your hands together for at least 20 seconds. This is about as long as it takes to sing "Happy Birthday" twice through.
  • Use hand sanitizer when washing isn't possible. Use an alcohol-based hand sanitizer when you can't get to a sink. Apply the hand sanitizer as you would hand lotion, making sure to completely cover the fronts and backs of both hands. Use a product that contains at least 60 percent alcohol.

Preventing diarrhea from contaminated food

To guard against diarrhea caused by contaminated food:

  • Serve food right away or refrigerate it after it has been cooked or reheated. Leaving food out at room temperature can encourage growth of bacteria.
  • Wash work surfaces frequently to avoid spreading germs from one food item to another. Wash your hands and your work surfaces several times during food preparation.
  • Use the refrigerator to thaw frozen items. Or try putting plastic-wrapped frozen items in a bowl of cold water to thaw. Don't leave frozen items on the counter to thaw.

Preventing traveler's diarrhea

Diarrhea commonly affects people who travel to developing countries, where diarrhea is sometimes due to inadequate sanitation and contaminated food and water. To reduce your risk:

  • Watch what you eat. Eat hot, well-cooked foods. Avoid raw fruits and vegetables unless you can peel them yourself. Also avoid raw or undercooked meats and dairy foods.
  • Watch what you drink. Drink bottled water, soda, beer or wine served in its original container. Avoid tap water and ice cubes. Use bottled water even for brushing your teeth. Keep your mouth closed while you shower. Beverages from boiled water, such as coffee and tea, are probably safe. Remember that alcohol and caffeine can aggravate diarrhea and dehydration.
  • Ask your doctor about using antibiotics. If you're traveling to a developing country for an extended period of time, ask your doctor about starting antibiotics before you leave on your trip. In certain cases, this may reduce the risk that you'll develop traveler's diarrhoea.

References:

http://www.who.int/mediacentre/factsheets/fs330/en/

https://www.hse.ie/eng/health/az/D/Diarrhoea/

http://www.imodium.ie/understanding-diarrhoea

https://en.wikipedia.org/wiki/Diarrhea

http://patient.info/health/acute-diarrhoea-in-adults-leaflet