Diarrhea Causes

What Are The Different Types And Causes of Diarrhea?

Diarrhea is the recurrent channel of loose, and watery, stools and major diarrhea causes include viral and bacterial infections.

Types of Diarrhea:

Acute: This lasts only for short time may be no longer than 24-hour period
Persistent: If there is diarrhea for more than 14 days
Chronic: Diarrhea is for more than 28 days

What are the Causes of Diarrhea?

  • A virus such as a norovirus, viral hepatitis and cytomegalovirus
  • Bacteria like Clostridium difficile, Escherichia coli, shigella and salmonella which might cause food poisoning
  • Parasites like cryptosporidium species

Other Causes of Diarrhea include:

What are the Chronic Causes of Diarrhea?

There are many diseases and conditions that can cause diarrhea, which includes:

Ulcerative Colitis:

This is a disease wherein the inflammation progresses in the colon and the rectum. Here diarrhea which is mixed with blood is the common symptom.

The symptom can vary from mild to severe. The diarrhea can also be mixed with mucus or pus. Frequency and urgency to the toilet are also most usual. Diarrhea can be watery as water cannot be absorbed well in the inflamed colon.

Crohn’s Disease:

Diarrhea is a usual symptom of Crohn’s disease. Symptoms severity varies from mild to severe. Flaring up and getting better depends on the inflammation. If Crohn’s disease is affecting the small intestine, then there might be watery diarrhea. If the colon is affected, then there might be bloody diarrhea. There will be urgency or incontinence when there is difficulty in controlling the bowel movements.

People with Crohn’s disease experience diarrhea due to inflammation as there will be much less absorption of water and sodium. This might also cause fluid leakage leading to watery diarrhea.


Most of the medications like antibiotics cause diarrhea, especially Clostridium difficile infection which is often caused after antibiotic course. This is because antibiotics finish both good and bad bacteria that can distract the natural balance of bacteria in body’s intestines. Cancer drugs and antacids with magnesium can also cause diarrhea.

Lactose Intolerance:

Some people cannot digest lactose which is a sugar found in milk and other dairy products. These individuals tend to experience diarrhea after having any milk products.


Fruits and honey contain a sugar called fructose, which is added as a sweetener to few beverages, which leads to diarrhea in individuals who have difficulty in digesting fructose.

Artificial Sweeteners:

Artificial sweeteners such as sorbitol and mannitol, which is commonly added to chewing gum and other sugar-free products, leads to diarrhea and healthy people can also experience diarrhea.


Individuals who are sensitive often experience diarrhea after undertaking abdominal or gallbladder surgery.


These includes Malabsorption Syndromes like Celiac disease, Irritable bowel Syndrome (IBS) etc.

Bacterial Diarrhea Causes

More serious diarrhea is caused by bacterial infections. Naturally, infection with bacteria happens after eating polluted food or drinks. The symptoms associated with these are fever, vomiting, and severe abdominal pain which can be serious. Bowel movements occur often and might be watery and people might experience “explosive diarrhea” that is defined as a very forceful, throwing out of loose, and watery stool along with gas.

If the stool contains pus or mucus or blood, then it would be considered as more serious. Many of the infections are related to local eruptions of disease. If at all the family members are eating the same food then they might get infected too.

Traveller’s diarrhea can also be one of the reasons as mentioned above. Fewer common causes are Escherichia coli, listeria and yersinia. Antibiotics use causes an overgrowth of Clostridium difficile bacteria in the intestines.

What are the Viral Diarrhea Causes?

Common causes of diarrhea also include viral infections that are classically related with mild-to-moderate symptoms with recurrent, watery bowel movements, a low-grade fever, and abdominal cramps. Viral diarrhea usually continues approximately 2 to 6 days.

Below are the most Common Causes of Diarrhea that are Caused by Viral Infections:

Infants are more susceptible to Rotavirus that causes diarrhea. Norovirusthat includes caliciviruses, Norwalk virus, is the major cause of increased diarrhea among adults and school-age children. The places of contamination include day care homes, schools, nursing homes, and restaurants. The one which is common in all age groups is adenovirus infections.

What are the Antibiotics Diarrhea Causes?

There are few people who are sensitive enough to medicines experience diarrhea when taking antibiotics. It can happen during the course of medicine or after finishing the antibiotic course. After few days, diarrhea will normally subside without any problem.

These type of diarrhea does not require any treatment as it is just a milder case. But people who are affected by Clostridium difficile bacteria after taking IV antibiotics or recently hospitalized and it can be severe diarrhea which requires treatment.

What are the Causes of Dehydration Diarrhea?

Dehydration is defined as a loss of body fluids that are made up of water and salts. One is aware that children when they are sick and have vomiting and diarrhea, then they tend to lose salt and water from the body which leads to dehydration. This can be very dangerous, particularly for infants, babies and children. If not treated immediately then it can be fatal. Dehydration to be treated otherwise it might require hospitalization.

It is very significant that the child with diarrhea always drinks and other appropriate quantity of fluids in order to avoid dehydration.

What are the Reasons for Diarrhea Caused by Food Intolerance?

Food intolerance happens when an individual has problems in food digestion particularly of few kinds of food. The symptoms can usually develop in an hour after eating the triggered food, it might develop after days also. Lactose is a major culprit for this type of diarrhea.

It is better to stay off from the foods which trigger the symptom of diarrhea to be on safer side. Keeping a diary to watch your diet is very helpful in these cases.

What are Bloody Diarrhea Causes?

Bloody diarrhea is a possibly dangerous condition in which there is blood present in along with loose, and watery stools. The blood can come from digestive tract or mouth to the anus. Diarrhea containing blood is normally an indication of gastrointestinal bleeding caused by injury or certain disease. Hematochezia is the name given to these type of diarrhea. If an individual has black, smelly and tarry diarrhea then it is called Melena. Bloody diarrhea is usually caused by a bacterial infection.

Bloody diarrhea can happen in all age groups and people. The lasting depends on the exact cause. If it is gastrointestinal infection then it can go away after treatment immediately. Bloody diarrhea can also persist over a longer period of time if it is chronic especially when the cause of it is inflammatory bowel disease.

What are the Watery Diarrhea Causes?

Inflammation of intestine or gastroenteritis causes watery diarrhea. The symptom is definite by stool which is more liquid in consistency and that is without blood. This is caused by bacterial infections, viruses, parasites or a diversity of noninfectious conditions.

What are Green Diarrhea Causes?

Green diarrhea might be little concern, nonetheless, suppose if it continues for many days. If the green diarrhea is not able to explain by a food source or any other common virus which causes vomiting and diarrhea, then it is high time to go to the doctor.

If the individual has one green diarrhea and the next bowel movement is of normal color then it is not a problem. Green diarrhea causes might be due to certain vegetable or any vitamin supplements taken if they are not green in color.

Medically Reviewed By
Dr. Kaushal M. Bhavsar (MBBS, MD)Assistant Professor in Pulmonary Medicine, GMERS Medical College, Ahmedabad