What is diarrhoea?

Diarrhoea is when stools (bowel movements) are loose and watery. It may cause your child to use the bathroom more frequently. Although it is a common problem, it can get worse if it lasts for more than two days, and your child may need to see a doctor. 

Diarrhoea generally has two types:

  • Short-term (acute): It goes away on its own, typically within a day or two. Its most common cause is a bacterial infection caused by food contamination . Diarrhoea may also occur when your child is unwell due to a virus.
  • Long-term (chronic): It lasts for weeks. Often, its causes are Irritable Bowel Syndrome (IBS), Giardia, or an intestinal disease such as Crohn’s disease, coeliac disease, or ulcerative colitis. 

Causes of Diarrhoea in children

Diarrhoea is not a condition but a symptom; it can often indicate a disease. It can occur in the following situations:

Viral Gastroenteritis

Children often catch viruses which can cause gastroenteritis, a bowel infection. Children are prone to highly contagious Viruses such as rotavirus, adenovirus, and astrovirus, which can all cause gastroenteritis. Special care should be taken in autumn and winter.

Viral gastroenteritis may cause mild fever and vomiting that lasts for one or two days. Diarrhoea in a liquified form that lasts for up to10 days is serious.

Bacterial gastroenteritis

Bacteria such as E. coli, Salmonella, shigella, and campylobacter — sometimes associated with food poisoning — can also cause gastroenteritis. It can result in high fever and blood or mucus in the stool, with a rapid onset. 


Gastroenteritis can also occur  because of parasites. Giardia and cryptosporidiosis are caused by a parasite that lives in water. In Australia, these parasites are found in streams, rivers, and lagoons, or almost any other places where water is found, such as swimming pools. 

Giardia often occurs in Aboriginal and Torres Strait Islander communities. It results in weight loss, tiredness, stomach aches due to serious diarrhoea. Cryptosporidiosis on the other hand is a liquified form of diarrhoea that causes vomiting, nausea, stomach ache, and loss of appetite. 


Antibiotics may also cause diarrhoea as they can get rid of both good and bad bacteria. This can leave bacteria in the gut out of balance and cause diarrhoea. Call a doctor if this is the cause of your child’s diarrhoea.

Clostridium difficile

This bacterium is also known as C.diff and often resides in the bowel of several children as well as a few adults. Its growth usually happens after the consumption of antibiotics and leads to serious gastrointestinal issues including high temperature, abdominal cramps, and watery diarrhoea. If it goes serious, you might witness blood in the stool. In these conditions, do not wait and take your child to the emergency.

What are long-term causes of diarrhoea?

The following conditions can be a cause of long-term diarrhoea in children:

Chronic constipation

It leads to the leakage of soft stools often without the person realising it. It happens when the person is severely constipated. This form of diarrhoea is called faecal incontinence or encopresis.

Lactose intolerance

All mammals including humans have lactose (sugar) found in milk. Babies and children are usually lactose tolerant however, some people are intolerant to lactose and can have stomach cramps and diarrhoea due to this.

Gastroenteritis can sometimes cause short-term lactose intolerance. Take your child to a doctor if this happens. Do not make amendments to their diet without consulting a doctor. 

Inflammatory bowel disease (IBD)

It is associated with Crohn’s disease and ulcerative colitis. It is hard to identify as its symptoms can outbreak and then be set aside. Weight loss occurs in children with IBD on an inapparent basis. 

Coeliac disease

It occurs when someone responds unusually to gluten. It leads to bloating, abdominal pain, and diarrhoea. Children with this disease grow much slower than normal children and can be a victim of weight loss. 


It is associated with many disorders that influence a person’s capacity to absorb nutrients from their food. Malabsorption may hinder the weight gain process of the child and cause constant diarrhoea. 

Your doctor might ask you a couple of questions related to your and your child’s diet on your visit. You will also be asked about your consumption of antibiotics. If it is short-term diarrhoea, you will not be bothered with any medical tests. In this case, the cause of diarrhoea will always be uncertain.

Pathophysiology of Diarrhoea in Children

Diarrhoea has the following mechanisms:

  • Osmotic
  • Secretory
  • Inflammatory
  • Malabsorptive

Osmotic diarrhoea 

It happens when several solutes (food components) stay in our gastrointestinal tract. These are insoluble and make it difficult for water to be absorbed, thus causing abnormal bowel movements, making it more liquid than solid. It can have severe symptoms including blood/mucus in stool, the inconsistent colour of stool, high temperature, and dehydration. Mild symptoms include bloating, nausea, and stomach pain. It is often caused by lactose in milk, carbohydrates in juices, or artificial sweeteners. It lasts for a few days and can be treated through diet adjustments.

Secretory Diarrhoea

It is caused due to bacterial toxins and viral infections that increase the emission of chloride ions and water in the intestinal lumen. It can be treated with drinks that use a mixture of salt, water, and glucose. 

Inflammatory diarrhoea

It is associated with frequent blood in the stool and also results in abdominal pain and fever. 

It is also related to conditions that cause ulceration of the intestinal mucosa. The blood, plasma, serum proteins, and mucous increase faecal bulk and the content of the fluids.

Symptoms of diarrhoea in kids

Children have different symptoms such as high fever, dehydration, blood in stools, nausea, bloating, abdominal cramps, frequent visits to the bathroom, and incontinence. You might confuse these symptoms with general health problems, however, see a doctor for a thorough check-up before the situation gets worse. 

How is diarrhoea diagnosed?

Your child’s medical and family history will be required on your initial visit. You should be well-versed about the time, causes, and symptoms of diarrhoea in your child to have a thorough discussion with their doctor, you will also be needed to discuss the diet, as well as the consistency and colour of their stool. 

You might be asked to take a follow-up on their diet and bowel habits.

How is diarrhoea treated? How to relieve diarrhoea in a child?

Medicine is not usually recommended for short-term diarrhoea in kids. It gets better once the body gets rid of the infection. Dr. Lazar regards diarrhoea as a cough where the body gets rid of all the bad things. Taking medicine would keep the infection inside and wouldn’t treat it accurately.

For more severe diarrhoea, ask your paediatrician for a thorough check-up.

Treatment of chronic diarrhoea in a child

The doctor will proceed with the treatment taking the age, general health, and symptoms into account. If diarrhoea causes dehydration, then your doctor will suggest treatment to regain the fluids in your child’s body. Your child might be given antibiotics if diarrhoea was caused by bacteria. 

Avoid giving plain water, juice or soda to your child as these can worsen the situation. Breastfeeding is highly effective as it increases the immunity of children however, you carry on with the formula milk if your child is used to it. In some cases, your child might be admitted to the hospital.

During this time, children should increase their fluid intake. In case of dehydration, give them glucose-electrolyte solutions. These drinks are effective and can also be taken in the form of popsicles.

Keep your doctor in the loop and follow everything accordingly. Take liquid foods and avoid solid foods until the diarrhoea is relieved. 

In underdeveloped countries, people suffer from chronic diarrhoea in large numbers. It is important to treat it on time to avoid serious issues. Patients must get themselves treated at high-end hospitals or centres for more accurate diagnosis.

Long-term diarrhoea can be treated while considering other treatment options as well. 

Antibiotics might be used to treat diarrhoea caused by infection or a parasite. Diarrhoea usually indicates different medical conditions, it gets easier to treat once the condition or cause is identified. Probiotics are used to fight diarrhoea by creating a healthy biome. Although healthcare providers believe these can be used as a treatment option, always consult your provider before consuming probiotics.

It is important to treat dehydration caused by diarrhoea. Once your child has recovered from diarrhoea, revert to a normal diet and fluids to overcome the dehydration caused. 

Breast-fed babies: Babies should continue with breastfeeding, it will further help with rehydration drinks. 

Bottle-fed babies: If the babies are back to their normal appetite, give them the formula milk in full strength, this would also add to overcoming dehydration

Older children:  Children must be offered food constantly as it would help them regain their energy. However, do not force food on your children. They can revert back to their normal diet, once their appetite is back. 

Diarrhoea in children can be taken care of by maintaining good hygiene. Children must wash their hands after using the washroom, touching pets, gardening, and before eating. It would help in the prevention of many bacterial infections that cause diarrhoea.

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