Loss of blood from the lining of the digestive tract, sometimes resulting in bloodstained faeces or vomit
- Age, gender, genetics, and lifestyle as risk factors depend on the cause
Bleeding can occur in any part of the digestive tract and should always be investigated because there may be a serious underlying cause. In some cases, only small amounts of blood are lost over a long period of time and go unnoticed. In other cases, severe, sudden bleeding from the digestive tract may result in blood being vomited or passed out of the anus in the faeces. You should seek medical help if you notice any bleeding.
What are the causes?
The causes of bleeding in the digestive tract include inflammation of or damage to the tract’s lining and tumours.
Bleeding from the upper tract, which includes the oesophagus, stomach, and duodenum, may occur if stomach acid damages the lining. This is a common complication of gastro-oesophageal reflux disease and peptic ulcers. Severe bleeding is sometimes due to enlargement of veins in the oesophagus, which may be a complication of chronic liver diseases (see Portal hypertension and varices).
Most cases of bleeding from the lower digestive tract, which includes the colon, rectum, and anus, are due to minor disorders, such as haemorrhoids or anal fissure caused by straining to defecate. However, bleeding may be a sign of colorectal cancer. Diverticular disease and other disorders of the colon can also lead to the presence of blood in the faeces.
What are the symptoms?
The symptoms vary according to the site and severity of the bleeding. If it is mild, blood loss may go unnoticed, but it may eventually cause symptoms of iron-deficiency anaemia, such as pale skin and shortness of breath. Severe bleeding from the oesophagus, stomach, or duodenum may cause:
Vomit containing bright red blood or resembling coffee grounds.
Black, tarry stools.
If there is a heavy loss of blood from the lower part of the tract, there will probably be visible blood in the stools. When there is severe blood loss from any part of the tract, shock may develop. Shock causes symptoms that include fainting, sweating, and confusion and requires immediate hospital treatment.
What might be done?
Minor bleeding may be detected only during an investigation for anaemia or screening to detect colorectal cancer. If the bleeding is severe, you may need intravenous fluids and a blood transfusion to replace lost blood. You will be examined to detect the location of the bleeding, usually by endoscopy through the mouth (see Upper digestive tract endoscopy) or anus (see Colonoscopy).
Treatment for bleeding depends on the underlying cause. For example, peptic ulcers are treated with antibiotics and ulcer-healing drugs, but colorectal cancer requires surgery. It may be possible to stop the bleeding during endoscopy. If the cause of the bleeding is identified and treated early, treatment is usually successful.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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