What should you know about gastroenteritis antibiotics?

Gastroenteritis can be caused by viruses, bacteria or other irritants. Antibiotics work against selected bacteria, not viruses, so they will not shorten a viral illness. Taking an unnecessary antibiotic can cause side effects and may make it harder to choose treatment later. Severe illness, blood in stools, persistent fever, recent travel, reduced immunity or a suspected bacterial infection may change the assessment. Rotavirus is another viral cause and also does not respond to antibiotics.

Replace lost fluid with frequent small sips of water or an oral rehydration drink. Rest and eat small, plain meals when your appetite returns. Do not use leftover antibiotics or someone else’s prescription. If a clinician prescribes an antibiotic, take it exactly as directed and report troublesome reactions. Wash hands with soap and water, clean soiled surfaces and avoid preparing food for others while infectious.

Seek urgent advice for severe dehydration, inability to keep fluids down, blood in vomit or stools, severe abdominal pain, confusion, fainting or fever with marked illness. Contact a clinician if diarrhoea is persistent, symptoms are worsening, or you have pregnancy, frailty, reduced immunity or a significant long-term condition.

Ask what cause is most concerning from your symptom pattern, whether a stool test is needed, and how to manage fluids alongside your usual medicines. If antibiotics are offered, ask what infection they target and which side effects require help.