Ulcerative colitis and vomiting blood: what to know

Blood in vomit can look bright red, dark brown, or like coffee grounds. Ulcerative colitis mainly affects the lining of the large bowel, so bleeding from the condition is more often noticed with bowel movements. Vomiting blood should therefore not be assumed to be an ulcerative colitis flare.

Haematemesis, the medical term for vomiting blood, can result from bleeding higher in the digestive tract. Possible causes include irritation or an ulcer in the stomach or food pipe, or a tear after forceful or repeated vomiting. Blood swallowed from the nose or mouth can also be brought up. Medicines that irritate the stomach or affect clotting may matter, so bring a list of every medicine, including non-prescription pain relief.

A flare of ulcerative colitis may cause bloody diarrhoea, urgency, and abdominal pain, but these symptoms do not explain away blood in vomit. Having both vomiting blood and bowel symptoms can lead to dehydration or blood loss and requires prompt clinical review.

Stop and seek emergency medical help now if you have vomited blood. Do not drive yourself if you feel faint, weak, confused, or unwell. Keep any vomit or note its colour and approximate amount if you can do so safely. Take your medicine list and ulcerative colitis treatment details with you.

Avoid alcohol and non-prescription anti-inflammatory painkillers unless a clinician has specifically told you to use them. Do not stop prescribed ulcerative colitis medicines on your own; tell the emergency team what you have taken and when. If you can swallow safely, take only small sips while arranging help, and do not delay assessment to eat or drink.

Vomiting blood is an emergency even if it happened once or the bleeding has stopped. Call emergency services immediately for dizziness, fainting, rapid breathing, severe weakness, pale or clammy skin, confusion, severe abdominal pain, black bowel movements, or continued bleeding. These can signal significant bleeding or shock.

A clinician may check your circulation, blood count, medicines, and symptoms, then decide whether tests or hospital treatment are needed. Do not wait for a routine appointment. For ongoing abdominal pain or diarrhoea without vomiting blood, arrange a prompt GP consultation.

Ask what the likely source of the blood is, whether your ulcerative colitis is active, and whether any medicine could be irritating your stomach or increasing bleeding risk. Ask which symptoms should prompt another emergency call and how to take your regular treatment while you recover.