Adenovirus diarrhoea: hydration and warning signs

Some adenovirus types infect cells lining the intestine. The inflamed bowel absorbs fluid less effectively and releases more fluid into the stool. Vomiting and fever can add to fluid loss. Children can become dehydrated more quickly because their fluid reserves are smaller.

Loose stools have many possible causes, so symptoms alone cannot identify adenovirus. A clinician considers recent illness, food or water exposure, medicines, travel, stool appearance and the examination. Testing is more likely when illness is severe, prolonged, bloody, linked to an outbreak or occurring in someone with reduced immunity.

Take frequent small sips of oral rehydration solution, which replaces water and salts in a balanced form. Continue breast milk and resume familiar foods as appetite returns. Very sweet drinks can worsen loose stools, and anti-diarrhoeal medicines may be unsuitable for children or for illness with blood or fever.

Wash hands with soap and water after using the toilet, changing nappies and before handling food. Clean frequently touched bathroom surfaces, do not share towels or utensils, and avoid preparing food for others while unwell. Antibiotics do not treat viral diarrhoea.

Get urgent help for marked drowsiness, confusion, fainting, severe or constant abdominal pain, green vomit, blood or black colour in stool, or an inability to keep fluids down. Dry mouth, no tears, sunken eyes, much less urine and increasing sleepiness point to dehydration and warrant prompt assessment.

Contact a clinician earlier for a young baby, an older or frail adult, pregnancy, reduced immunity, kidney disease, or diarrhoea that is worsening rather than settling. These circumstances can change the choice and urgency of fluid treatment.

Tell the clinician about urine output, vomiting, stool colour, abdominal pain, fever, travel, recent antibiotics and whether anyone else is ill. Ask whether oral rehydration is enough, whether a stool test is useful, and which medicines should be paused or avoided during dehydration.