Common stomach bug symptoms

Common stomach bug symptoms include diarrhoea, nausea, vomiting, abdominal cramps, loss of appetite and sometimes fever. Symptoms may begin suddenly and can leave you weak or thirsty. Gastroenteritis may be caused by an infection, and symptoms can vary between people, especially in young children, older adults and those with other health conditions.

Gastroenteritis irritates the stomach and intestines, leading to loose stools, nausea, vomiting or cramping. Fever can occur as the immune system responds. Rotavirus Infection is one possible cause, particularly in children, but not every stomach bug has the same cause. The main concern is dehydration from losing fluid through diarrhoea or vomiting. Signs can include unusual thirst, dry mouth, reduced urination, dizziness, marked tiredness or dark urine. Symptoms can overlap with food poisoning and other illnesses, so context matters.

Take frequent small sips of water or an oral rehydration solution, especially after vomiting or a loose stool. Once tolerated, eat light foods and return gradually to your usual diet; do not force food when nausea is strong. Rest, wash hands thoroughly and avoid preparing food for others while infectious symptoms continue. Do not give anti-diarrhoeal or anti-vomiting medicines to children without medical advice. Monitor urination, alertness and the ability to keep fluids down.

Seek urgent help for severe dehydration, confusion, fainting, blood in vomit or stool, severe or localised abdominal pain, a stiff neck, breathing difficulty or inability to keep fluids down. Contact a clinician for persistent fever, worsening symptoms, repeated vomiting, very little urine, or symptoms in a very young child, older adult or medically vulnerable person. Emergency care is needed if the person is difficult to wake or appears seriously unwell.

How can I replace fluids safely? Could this be dehydration or another infection? When can I return to work, school or food preparation? Which symptoms mean my child or I need urgent assessment?