What should you know about vomiting and defecating blood?

Blood may look bright red, dark brown or like coffee grounds in vomit. In stool, it may appear as bright red blood or make the stool black and tar-like. The appearance can help a clinician locate the bleeding, but it cannot identify the cause by itself.

Bleeding can come from the throat, stomach or upper intestine, or from farther along the bowel. Repeated retching can irritate the lining, while inflammation, an ulcer, enlarged veins, or another digestive problem can also cause bleeding. Swallowed blood from a nosebleed or mouth injury may sometimes be vomited, but this still deserves medical advice when the amount is more than a trace or the source is unclear.

Food Poisoning, Gastroenteritis and Rotavirus Infection can cause vomiting or diarrhoea, but blood is not something to assess at home as a routine part of an infection. Gallstones and Pancreatitis may cause severe upper-abdominal pain and vomiting; a clinician needs to examine you to distinguish these problems from bleeding and other causes.

Arrange urgent medical assessment, especially if the bleeding has happened more than once or you feel unwell. Do not drive yourself if you feel faint, confused or weak. Keep a note of the colour and amount, when it started, whether you have abdominal pain or diarrhoea, and which medicines you take.

Avoid alcohol and do not take aspirin, ibuprofen or other anti-inflammatory painkillers unless a clinician has specifically told you to use them. Do not eat or drink large amounts while actively vomiting. If you are alert and not vomiting repeatedly, take small sips of water while arranging care, unless a clinician has given different instructions.

Call emergency services or go to an emergency department immediately if there is a large amount of blood, coffee-ground vomit, black tar-like stool, fainting, severe dizziness, confusion, clammy skin, fast breathing, severe abdominal pain, or difficulty staying awake. These signs can occur when bleeding is significant or when the body is becoming unstable.

Seek urgent help as well if you take blood thinners, have known liver disease, are pregnant, or cannot keep fluids down. While waiting, lie on your side if you are drowsy or still vomiting, and take your medicine list with you.

Ask: Where might the bleeding be coming from? Do I need blood tests, a camera examination, scans or observation? Should I stop or change any regular medicine? What symptoms mean I should return immediately? Tell the clinician about previous ulcers or digestive bleeding, alcohol use, recent vomiting, liver problems, and any blood-thinning or anti-inflammatory medicines.