Diarrhoea: symptoms and causes - THDLAB - CO UK

  • What is diarrhoea
  • Symptoms of diarrhoea
  • Causes of diarrhoea
  • Diarrhoea and dysentery: differences

What is diarrhoea

Diarrhoea is a defecation disorder characterised by the rapid and frequent emission of mainly liquid faeces. Diarrhoea is characterised by the following conditions:

  • at least 3 evacuations a day;
  • alterations in the quantity or quality of the evacuations with poorly formed stools (liquid or semi-liquid)

In normal situations, the water content of the faeces is about 100 ml/day. If the water content exceeds 200 ml/day and is associated with 3 or more evacuations a day, diarrhoea is indicated. In many cases diarrhoea is also associated with rectal tenesmus which is the frequent stimulus to evacuate even in the absence of faeces.

Like constipation, diarrhoea is not an actual disease but a symptom of intestinal dysfunction common to various diseases or to different non-pathological conditions.

Many people underestimate diarrhoea, considering it a trivial disorder, linked to stress, nutrition or climatic variations. However, diarrhoea is often the body’s defence response which aims to eliminate pathogenic microorganisms or toxins. It is therefore inadvisable to use anti-diarrhoeal medicines before discovering the causes of the disorder.

Based on the persistence of the disorder and its frequency, we can distinguish between acute diarrhoea, chronic diarrhoea and recurrent diarrhoea.

  • acute diarrhoea: lasts less than 2 weeks and often resolves spontaneously without the need for specific treatment. Acute diarrhoea is very common in the population and in many cases is of viral origin. However, in the presence of dehydration, fever and tachycardia, you should contact your doctor as soon as possible.
  • chronic diarrhoea: persistent diarrhoea lasting more than 2-3 weeks may indicate a more serious problem and lead to severe dehydration. The body also undergoes electrolytic alterations which can cause low blood pressure, metabolic acidosis, tachycardia and lethargy. Chronic diarrhoea can become dangerous especially for children, the elderly and debilitated individuals. In the event of severe dehydration, prolonged diarrhoea may make hospitalisation necessary.
  • recurrent diarrhoea: a disorder with cyclical progression and episodes of diarrhoea in quick succession. If diarrhoea occurs periodically it is advisable to consult your doctor.

Symptoms of diarrhoea

In addition to the frequent emission of poorly formed stools, according to the severity and cause, diarrhoea can be associated with the following symptoms:

  • cramps
  • abdominal swelling
  • abdominal pain
  • nausea
  • defecatory urgency
  • fever
  • traces of blood and/or mucus in the stools

In the presence of symptoms such as fever, blood in the stools and severe abdominal pain it is important to contact your doctor as soon as possible.


Causes of diarrhoea

There are many causes of diarrhoea and they can vary greatly. The most common causes of diarrhoea are:

  • Infections: bacterial infections and viral infections can lead to the onset of diarrhoea. Bacterial infections are more frequent in the summer, while viral forms are more common in winter. Water and food contaminated with bacteria such as salmonella and campylobacter can cause diarrhoea. While diarrhoea caused by viral infections is caused by several viruses, including rotavirus, Norwalk virus, cytomegalovirus.
  • Parasites: some parasites can penetrate the body through the intake of water and food and cause diarrhoea. Among these parasites we have entamoeba histolytica and giardia duodenalis.
  • Psychological causes: stress, anxiety and strong tension can trigger episodes of diarrhoea, which often resolve spontaneously.
  • Intestinal inflammations: some inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis.
  • Bowel Disorders: Irritable Bowel Syndrome.
  • Medicinal products: taking certain categories of medicines such as laxatives, NSAIDs, antibiotics and chemotherapy.
  • Foods: intolerances and allergies to some foods, such as artificial sweeteners and lactose.
  • Anatomical lesions and surgery: anatomical lesions, in particular following operations such as an intestinal bypass, or surgical procedures such as gall bladder removal.
  • Endocrine causes: endocrine disorders such as hyperthyroidism and diabetes.
  • Neoplasms: intestinal carcinomas and lymphomas.

Acute forms of diarrhoea are often caused by bacterial, viral infections or parasites. On the contrary, chronic diarrhoea is usually linked to functional disorders or inflammation of the intestine.

Diagnosis of the underlying cause of diarrhoea is essential for identifying the most appropriate treatment pathway.

For this reason, especially in the presence of chronic and recurrent diarrhoea, it is necessary to undergo a rectal examination.


Diarrhoea and dysentery: differences

The words diarrhoea and dysentery, often used as synonyms, actually indicate two different disorders.

Diarrhoea is a disorder characterised by at least three evacuations a day of liquid or semi-liquid stools.

Dysentery is instead a gastroenteritis of infectious origin which manifests itself with diarrhoea and blood in the stool which is visible to the naked eye. Along with diarrhoea and blood or mucus in the stool, dysentery can be associated with stomach cramps, high fever, nausea or vomiting.

Some international organisations such as the English NHS have classified dysentery as an intestinal infection which causes diarrhoea containing blood or mucus.

The World Health Organisation (WHO) indicates Shigella or Entamoeba histolytica infections among the most frequent causes of dysentery:

  • bacillary dysentery, caused by a bacterium of the Shigella species, more frequent in temperate climatic areas.
  • amoebic dysentery, caused by the amoeba Entamoeba histolytica, widespread mainly in tropical areas and exotic countries. In this case, dysentery often affects those who ingest water or contaminated food.