What should you know about black vomit after chemotherapy?

Call the oncology emergency number immediately or go to an emergency department. If the person is faint, confused, difficult to wake, severely weak, short of breath, or actively vomiting blood, call emergency services rather than travelling without medical support.

Blood exposed to stomach acid can become dark and granular, resembling coffee grounds. Bleeding may arise from irritation, an ulcer, forceful retching, or another problem in the oesophagus or stomach. Chemotherapy can also lower platelets, which help blood clot, or irritate digestive tissues.

Some foods, iron, or medicines can darken stomach contents, but it is not safe to assume this explains black vomit after cancer treatment. Clinicians need to assess circulation, blood counts, medicines, and the possible source.

Do not take another chemotherapy dose or non-prescribed pain medicine while waiting for instructions. Avoid food and drink if vomiting is continuing or emergency staff advise this. Do not drive if dizzy or weak.

Bring the chemotherapy schedule and complete medication list, including blood thinners, steroids, pain medicines, and supplements. Tell the team when vomiting began, what it looked like, how often it occurred, and whether there is black stool, abdominal pain, fever, bruising, or reduced urine.

Call emergency services for bright-red or repeated bloody vomit, collapse, confusion, clammy or pale skin, a racing heartbeat with weakness, severe abdominal or chest pain, breathing difficulty, or inability to stay awake. These signs can accompany significant blood loss or another acute complication.

Ask what may have caused the bleeding, whether blood counts or clotting are affected, which medicines should be paused or continued, how nausea will be controlled, and how the event changes the timing or dose of future treatment.