Gastrointestinal bleeding

Gastrointestinal bleeding means blood is being lost somewhere in your digestive tract. This tract includes the food pipe, stomach, small intestine, large intestine, rectum, and anus.

Bleeding may be obvious, such as red blood in the toilet. It can also be hidden and found only through a stool test or blood test. Slow blood loss may cause anaemia, meaning there are too few healthy red blood cells.

The appearance of the blood offers clues, but it cannot confirm where the bleeding comes from. Even a small amount deserves medical advice if there is no clear, previously assessed explanation.

Gastrointestinal bleeding may appear as:

• Bright red blood on toilet paper or around the stool
• Red or dark red blood mixed with stool
• Black, sticky, tar-like stool with a strong smell
• Vomit containing red blood
• Dark, grainy vomit that resembles coffee grounds

Bleeding itself may not hurt. Depending on its cause, you might also have abdominal pain, pain during a bowel movement, diarrhoea, nausea, or indigestion.

Slow blood loss can cause tiredness, shortness of breath, headaches, pale skin, or reduced ability to exercise. Faster or heavier bleeding may cause dizziness, fainting, confusion, a racing heartbeat, or cold and clammy skin.

Iron tablets, medicines containing bismuth, and some foods can darken stool. However, black, tarry stool should not be assumed to come from food or medicine without medical advice.

Common causes near the anus include hemorrhoids and anal fissures. Hemorrhoids are swollen blood vessels. A fissure is a small tear, often caused by hard stool. Both may leave bright red blood on toilet paper, although other conditions can look similar.

Common causes higher in the digestive tract include stomach or duodenal ulcers. The duodenum is the first part of the small intestine. Inflammation of the stomach lining or food pipe can also bleed. Anti-inflammatory pain medicines, such as ibuprofen and naproxen, can contribute to ulcers or irritation.

Other possible causes include small pouches in the colon called diverticula, bowel inflammation, abnormal blood vessels, polyps, and complications of liver disease. Less commonly, bleeding can be related to cancer of the stomach, bowel, or another digestive organ.

Some causes, including a severely bleeding ulcer, a tear after forceful vomiting, reduced blood flow to the bowel, or enlarged veins in the food pipe, can require urgent treatment. The amount or colour of blood alone cannot identify the cause.

Call emergency services or go to an emergency department now if:

• You are vomiting blood or coffee-ground-like material
• Bleeding is heavy, continuous, or includes large clots
• You faint, feel confused, or cannot stand because of dizziness
• You have breathing difficulty, cold clammy skin, or marked weakness
• Bleeding occurs with severe or sudden abdominal pain

Seek same-day medical care for black, tarry stool; dark red stool; bloody diarrhoea; or repeated visible bleeding, even if you otherwise feel well. You should also seek prompt advice if you take a blood thinner or have liver disease.

Book a routine appointment for a small amount of bleeding that has stopped, unless a clinician has already assessed the same recurring pattern and given you a plan. Arrange follow-up for unexplained tiredness, anaemia, persistent bowel changes, unplanned weight loss, or a positive stool blood test.

A healthcare professional will ask what the blood looked like, how much you noticed, and whether you had pain, vomiting, constipation, or diarrhoea. They may ask about alcohol use, liver disease, previous bleeding, and medicines such as aspirin, anti-inflammatory painkillers like ibuprofen or naproxen, or blood thinners like warfarin or apixaban.

An examination may include checking your pulse and blood pressure and examining your abdomen or rectum. Blood tests can look for anaemia, clotting problems, and signs that organs are under strain.

An upper endoscopy uses a flexible camera passed through the mouth. A colonoscopy examines the large bowel through the anus. Depending on the situation, testing may instead include stool tests, CT imaging of blood vessels, or a swallowable capsule camera.

Treatment depends on the source, amount, and speed of bleeding. A procedure during endoscopy may seal a bleeding vessel, inject treatment, apply a clip, or use heat. Other care may include acid-suppressing medicine, fluids, iron replacement, blood transfusion, radiology procedures, or surgery.

Do not rely on home treatment for visible gastrointestinal bleeding. Avoid taking additional aspirin, ibuprofen, or naproxen for pain while awaiting advice because these can worsen some types of bleeding. Do not stop a prescribed blood thinner or antiplatelet medicine on your own; contact the prescribing service urgently for instructions.

If you feel faint or weak, do not drive yourself for care.

A small bleed from a fissure may stop quickly, while bleeding from an ulcer or bowel condition can continue or return until the cause is treated. Blood counts may take longer to recover than the visible bleeding takes to stop.

Follow-up may include repeat blood tests, medicine review, treatment of constipation or inflammation, or further investigation. Return for urgent care if bleeding recurs heavily or you develop dizziness, fainting, breathlessness, or severe pain.

Does bright red blood always mean hemorrhoids?

No. Hemorrhoids are common, but fissures, bowel inflammation, diverticular disease, polyps, and other conditions can also cause red blood.

Does black stool always mean bleeding?

No. Iron, bismuth, and some foods can darken stool. Bleeding higher in the digestive tract can produce black, sticky, tar-like stool, which needs prompt assessment.

Can bleeding happen without visible blood?

Yes. Small amounts may be detected through a stool test. Ongoing hidden bleeding may first appear as iron-deficiency anaemia, tiredness, or shortness of breath.

Should I stop my blood thinner?

Do not stop it without professional advice. Suddenly stopping some blood thinners can increase the risk of a blood clot or stroke. Seek urgent instructions if bleeding occurs.