​Diarrhea:
It is a very common condition, which occurs in most people several times each year, it is defined as the release of loose or watery stools usually three or more times in a 24-hour period.

Types of Diarrheas:
There are several different ways to classify diarrhea, as these types include:

• Severe diarrhea: The most common is flaccid watery diarrhea that lasts from 1, 2 to 14 days, this type does not need treatment and it usually goes away after a few days.
• Persistent diarrhea: This type of diarrhea generally lasts for several weeks, from two to four weeks but less than 30 days.
• Chronic diarrhea: Diarrhea that lasts more than four weeks (more than 30 days) or it comes and goes regularly over a long period.

Causes:
The cause of most cases of intestinal diarrhea has not been generally identified, but the most common cause of diarrhea is a virus that infects the intestine. The infection usually lasts two days and it is sometimes called "intestinal influenza". Possible causes can include:

• Eating foods that upset your gastrointestinal system.
• Malabsorption of food.
• Viruses
• Bacteria that live in food or water
• Parasites (e.g., small worms)
• Side effects of some medications
• Problems   digesting certain types of food.
• Diseases that damage the Gastrointestinal System (e.g., lactose intolerance)

Those most vulnerable to:
Anyone can get diarrhea however diarrhea can be serious in certain groups of people, including:

• Children.
• Elderly people.
• People with medical problems.

Symptoms:
Three or more times of watery diarrhea per day are the main symptoms, and people with diarrhea may experience one or more of the following symptoms:

• Urgent need to use the bathroom.
• Loss of bowel movement control
• Nausea
• Abdominal pain

People with diarrhea caused by certain infections may experience one or more of the following symptoms:

• Bloody stools
• High fever and chills
• Dizziness
• Vomiting

When to see a doctor:

• When diarrhea does not improve or disappear.
• Diarrhea more than 6 times in 24 hours.
• Blood with diarrhea.
• High fever rises above 38.5°C.
• Severe abdominal pain.
• When symptoms of dehydration are observed, these symptoms can include:

1. Dark urine and small amounts of urine or loss of urine production.
2. Feeling thirsty.
3. Rapid heart rate.
4. Headache.
5. Skin dryness.
6. Drowsiness and Dizziness.
7. Severe nausea, vomiting and inability to tolerate or retain anything by mouth.

Complications:
Dehydration is a serious complication of diarrhea, and it occurs as a result of fluid loss by the body.

Diagnoses:
Many people don't need examinations, but your doctor will likely do examinations to check if you're dehydrated or to find out what's causing your diarrhea.

Treatment:
In most cases, mild diarrhea can be treated at home. If the diarrhea is caused by an infection or parasites, you will need to visit a health care provider for treatment. When the diarrhea lasts for a long time (several weeks), the health care provider will base the treatment on the cause. This may include a few different treatment options, including:

• Antibiotics: To treat the infection that causes diarrhea, whether bacterial or parasitic.
• Medication for a specific condition: Diarrhea can be a sign of many other medical conditions including irritable bowel syndrome, Crohn's disease, ulcerative colitis, or bacterial overgrowth.
• Probiotics: Groups of beneficial bacteria are sometimes used to recreate a healthy biome to fight diarrhea, it can be useful in some cases.

Prevention:

• Wash hands before and after changing diapers, cooking, eating, going to the bathroom, taking out garbage, touching animals, touching the nose.
• Store food properly: by keeping food at the proper temperatures, cooking food up to the recommended temperature and handling all food safely.
• Traveler's diarrhea can occur when drinking water or other beverages that have not been treated properly, so avoid drinking tap water, using ice cubes, brushing teeth with tap water, consuming unpasteurized milk, dairy products, or unpasteurized juices, and you must be careful when trying local foods from street vendors, eating raw or undercooked meat (and shellfish), as well as raw fruits and vegetables, and in case of doubt, drink bottled water or anything that has been boiled first (such as coffee or tea).
• Cook meat and seafood until to be well cooked.
• Cook the eggs until the yolks are firm.
• Wash hands, knives and cutting boards after touching raw food.

Tips for people with diarrhea:
 Foods that may worsen diarrhea should be avoided:

• Caffeinated beverages and foods
• Dairy products (e.g. milk, cheese, ice cream).
• Fatty foods
• Drinks and foods containing fructose.
• Fruits (e.g. apple, peach, pear)
• Spicy food.
• Diet drinks, sugar-free gum and sweets containing sweeteners (e.g. sorbitol, mannitol, xylitol)
• Research shows that a restricted diet does not help treat diarrhea in most cases, and most experts do not recommend fasting or a restricted diet when diarrhea occurs.