Bleeding in the digestive tract
Bleeding can be a symptom of medical conditions such as piles, or haemorrhoids.
Doctors will need to find the source of the bleeding in the digestive or gastrointestinal (GI) tract, which includes the oesophagus, stomach, small intestine, colon, rectum, and anus. Bleeding can come from one or more of these areas, that is, from a small area such as an ulcer on the lining of the stomach or from a more diffuse problem such as inflammation of the colon.
Bleeding can sometimes occur without you even knowing about it. This type of bleeding is called occult or hidden. Fortunately, simple tests can detect occult blood in the stools.
What causes bleeding in the digestive tract?
Bleeding from the oesophagus can be caused by:
- Oesophagitis and gastro-oesophageal reflux. Stomach acid that refluxes (returns) back into the oesophagus from the stomach can cause an irritation and inflammation of the oesophagus (oesophagitis) that may lead to bleeding.
- Varices. Abnormally enlarged veins located at the lower end of the oesophagus, called varices, may rupture and bleed massively. Cirrhosis of the liver is the most common cause of oesophageal varices.
- Mallory-Weiss tear. This is a tear in the lining of the oesophagus that usually is caused by prolonged vomiting but may also result from other causes of increased abdominal pressure, such as coughing, hiccupping or childbirth.
Bleeding from the stomach can be caused by:
- Gastritis. Alcohol, medications including NSAIDs (non-steroidal anti-inflammatory drugs) such as aspirin, or ibuprofen, and many others can cause stomach ulcers or inflammation (gastritis).
- Stomach ulcers and intestinal ulcers. Ulcers in the stomach may enlarge and erode through a blood vessel, causing bleeding. Aside from medication, the most common cause of a stomach ulcer is an infection with a bacterium called Helicobacter pylori. Also, patients suffering from burns, shock, head injuries, or cancer, as well as those who have undergone extensive surgery, may develop stress-related stomach ulcers.
- Cancer of the stomach.
Bleeding from the lower digestive tract (colon, rectum, and anus) can be caused by:
- Haemorrhoids. These are probably the most common cause of visible blood passed from the lower digestive tract, especially blood that appears bright red. Haemorrhoids are enlarged veins in the anal area that can rupture and produce bright red blood, which can show up in the toilet or on toilet paper.
- Anal fissures. Tears in the lining of the anus can also cause bleeding.
- Colon polyps. These are growths that can occur in the colon. They can be the precursor of cancer and may cause bleeding.
- Colorectal cancer.
- Intestinal infections. Inflammation and bloody diarrhoea can result from intestinal infections.
- Ulcerative colitis. Inflammation and extensive surface bleeding from tiny ulcerations can be the reason for blood showing up in the stool.
- Crohn's disease. This chronic condition also causes inflammation and can result in rectal bleeding.
- Diverticular disease. Caused by diverticula - out-pouchings of the colon wall.
- Blood vessel abnormalities. As one gets older, abnormalities may develop in the blood vessels of the large intestine, which may result in recurrent bleeding.