Green diarrhoea and food poisoning: what to know

Bile is naturally greenish and usually changes colour as it travels through the intestine. When diarrhoea moves rapidly, bile may remain visible, giving stools a green appearance. Food dyes, leafy vegetables, or supplements can also affect colour. Food poisoning may also bring cramping, nausea, vomiting, or fever; these symptoms describe the illness pattern, but colour alone cannot identify its cause. Read more about [Food Poisoning](/conditions/food-poisoning/), [Diarrhoea](/symptoms/diarrhoea/), [Abdominal Pain](/symptoms/abdominal-pain/), and [Fever](/symptoms/fever/).

Take frequent small sips of water or an oral rehydration drink, especially after each loose stool or episode of vomiting. [Oral Rehydration Therapy](/treatments/acute-and-urgent-care/oral-rehydration-therapy/) replaces fluid and salts more effectively than relying on plain water alone. Eat light foods when you feel able, and avoid alcohol and foods that clearly worsen symptoms. Wash hands carefully and avoid preparing food for others while unwell. [Nausea](/symptoms/nausea/) and [Vomiting](/symptoms/vomiting/) can make drinking difficult, so try spoonfuls or small sips rather than a large glass.

Seek urgent medical help for faintness, confusion, very little urine, severe weakness, persistent vomiting, severe abdominal pain, blood or black stool, or a fever that is high or ongoing. These can signal dehydration or a more serious infection. A clinician may recommend [IV Fluid Therapy](/treatments/acute-and-urgent-care/iv-fluid-therapy/) when fluids cannot be kept down or dehydration is significant. Contact a clinician if diarrhoea is not settling, symptoms are worsening, or you have a condition that makes dehydration more hazardous.

Ask: Could the colour be from food or medicine? How much should I drink while symptoms continue? Which warning signs mean I need urgent assessment? Should anyone else who ate the same food be checked?