What to know about a 24-hour stomach bug

Typical features include watery diarrhoea, nausea, vomiting, abdominal cramps and sometimes fever. The main immediate concern is dehydration from losing fluid and salts.

“Stomach bug” is an informal name for gastroenteritis, often caused by an infection affecting the stomach and intestines. It is not the same as influenza, which mainly affects the airways.

The label “24-hour” does not set an exact timetable. Vomiting may settle before diarrhoea, appetite can remain low for a while, and recovery varies with the cause and the person’s health.

Take frequent small sips of water or an oral rehydration solution; this may be easier to keep down than a large drink. When hungry, restart ordinary food in small portions and avoid forcing a meal.

Wash hands thoroughly with soap and water after using the toilet and before handling food. Do not prepare meals for other people while vomiting or diarrhoea continues, and clean frequently touched bathroom surfaces.

Check with a pharmacist or clinician before using anti-diarrhoeal medicine, particularly for a child or when there is fever or blood in the stool.

Seek urgent medical care for fainting, confusion, severe or worsening abdominal pain, blood or black material in vomit or stool, or an inability to keep fluids down. Very little urine, a very dry mouth, marked weakness or unusual drowsiness can indicate dehydration.

Contact a clinician earlier for a baby, an older adult, someone who is pregnant, or a person with reduced immunity or significant long-term illness. Arrange an assessment if symptoms are not easing, return after improvement, or follow recent travel or antibiotic use.

Ask whether your symptoms or medicines raise the risk of dehydration, whether a stool test is appropriate, and which fluids or medicines are suitable for you. Mention recent travel, sick contacts, unusual meals and antibiotic use.