Bacteria and stomach flu

Gastroenteritis means inflammation of the stomach or intestines. Viruses are common causes, but bacteria can enter through contaminated food or water, undercooked food, unwashed hands, or contact with an infected person. Symptoms may include sudden diarrhoea, abdominal cramps, nausea, vomiting, fever and loss of appetite. The pattern can overlap with rotavirus infection and other illnesses, so symptoms do not prove that bacteria are responsible. A clinician may ask about meals, travel, household illness, recent medicines and symptom timing. Testing a stool sample may be considered when illness is severe, prolonged, bloody, associated with significant fever, or important for public-health decisions.

Replace lost fluid with frequent sips of water or an oral rehydration solution. Eat small, plain meals when able, and avoid alcohol until you are recovering. Wash hands carefully with soap and water, use separate towels where possible, and avoid preparing food for others while diarrhoea or vomiting continues. Do not start leftover antibiotics: some bacterial illnesses need specific treatment, while antibiotics are unhelpful for many causes and can sometimes worsen diarrhoea. A pharmacist or clinician can advise about symptom medicines, particularly for children, pregnancy, older age or long-term illness.

Contact a clinician promptly if there is blood in diarrhoea, severe abdominal pain, ongoing vomiting, a concerning fever, worsening weakness, or signs of dehydration such as very little urine, intense thirst, dizziness or confusion. Seek urgent help for fainting, inability to drink, severe drowsiness or breathing difficulty. Infants, older adults, pregnant people and people with weakened immunity may need earlier assessment. Arrange review if diarrhoea is not improving or if symptoms return after initial recovery.

Ask whether your history suggests a stool test or a particular treatment. Tell the clinician about recent antibiotics, travel, restaurant or shared meals, sick contacts, blood or mucus in stool, fluid intake and urine output. Ask when you can safely return to work, school or food handling and how to protect household members.