Diarrhoea? What’s responsible?


Diarrhoea is most commonly due to viral gastroenteritis with rotavirus, which accounts for 40% of cases in children under five.

Gastroenteritis or infectious diarrhoea is a medical condition from inflammation of the gastrointestinal tract that involves both the stomach and the small intestine. It causes many effects like a combination of diarrhea, vomiting, and abdominal pain and cramping. Dehydration may occur as a result. Gastroenteritis has been referred to as gastro, stomach bug, and stomach virus.

Rotavirus is the most common cause of severe diarrhoea among infants and young children under 5 years of age. It is a genus of double-stranded RNA virus in the family Reoviridae. Nearly every child in the world has been infected with rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe; adults are rarely affected. There are eight species of this virus, referred to as A, B, C, D, E, F, G and H. Rotavirus A, the most common species, causes more than 90% of rotavirus infections in humans. The virus is transmitted by the fæcal-oral route. It infects and damages the cells that line the small intestine and causes gastroenteritis (which is often called "stomach flu" despite having no relation to influenza). Rotavirus accounts for 50 percent of cases of hospitalization yet has been vastly underestimated by Public Health practitioners especially in developing countries.

Bacterial infections predominate in travellers. Various toxins such as mushroom poisoning and drugs can also cause acute diarrhoea.

Chronic diarrhoea can be the part of the presentations of a number of chronic medical conditions affecting the intestine. Common causes include ulcerative colitis, Crohn's disease, microscopic colitis, celiac disease, irritable bowel syndrome and bile acid malabsorption.