What should you know about an E. coli stomach bug?

E. coli are bacteria found in different environments, including the gut. Some types can irritate the digestive tract after contaminated food or water, or contact with an infected person or animal. The illness may resemble other forms of gastroenteritis, so symptoms alone cannot confirm E. coli.

Loose stools, cramping, nausea, vomiting, tiredness and a raised temperature may occur. Blood in the stool is a reason to seek medical advice, because some E. coli infections can affect the bowel more seriously. Diarrhoea and vomiting can lead to dehydration, especially in young children, older adults and people with other illnesses.

Take frequent small sips of water or an oral rehydration drink. Continue eating light foods when you feel able, and avoid preparing food for other people while symptoms continue. Wash hands carefully with soap and water after using the toilet and before eating; clean commonly touched bathroom surfaces.

Do not start antibiotics or anti-diarrhoeal medicine without medical advice. Some infections need testing, and certain medicines may be unsuitable when there is blood in the stool or a fever. A clinician may ask about recent meals, travel, contacts and symptoms, and may arrange a stool test.

Arrange prompt medical advice for bloody diarrhoea, severe or worsening abdominal pain, repeated vomiting, a high temperature, marked weakness, confusion, very little urine or difficulty keeping fluids down. Seek urgent help if you become faint, unusually drowsy or unable to drink.

Contact a clinician sooner for a baby, an older adult, pregnancy, a weakened immune system or a significant long-term condition. Diarrhoea that does not start settling also deserves assessment. See the pages on dehydration, diarrhoea and abdominal pain for related guidance.

Ask whether your symptoms need a stool test, which fluids are suitable, whether you should avoid work or food preparation, and which warning signs should bring you back for review.