Hidden, or occult, bleeding can be a sign of serious health problems, yet many people are unaware of this condition as it is not visible to the naked eye. This type of blood loss originates in the digestive system and can often only be detected through specific tests, such as a faecal occult blood test. As the symptoms may initially be mild or even imperceptible, the timely detection of occult bleeding is crucial for the early diagnosis of underlying conditions, including bowel cancer.
Many people are apprehensive about medical examinations, particularly those involving the digestive system. However, it is important to understand that occult bleeding is not a disease in itself, but a symptom that requires attention. Modern medicine, for example, the Endomedix Gastroenterology Centre Thanks to their expertise, they offer pain-free and effective methods for diagnosis and the necessary treatments.
In this article, we explain in detail what hidden bleeding is, what might be causing it, and what lifestyle changes you can make to reduce the risks. Our aim is to provide clear and reassuring information to help you take confident steps to look after your health.
What is occult (hidden) bleeding?
Occult or hidden bleeding refers to a small amount of blood loss originating from the digestive system that is not visible to the naked eye in the stools. The volume of blood loss is typically less than 100 ml per day. As the bleeding is not visible, patients are often asymptomatic or experience only generalised symptoms, such as tiredness and weakness caused by iron-deficiency anaemia.
Occult bleeding can occur anywhere in the digestive tract, from the oesophagus right down to the rectum. The location of the source of the bleeding may affect the appearance of the blood in the stools, but in the case of occult bleeding, the amount is too small to cause any visible changes. A diagnosis requires specialised laboratory tests capable of detecting even the smallest amounts of blood.
Detection of occult blood
Stool tests are most commonly used to detect occult bleeding. There are two main types:
- Guaiac-based faecal occult blood test (gFOBT): This older type of test detects the peroxidase activity of the haem component of haemoglobin in the blood. The test is highly sensitive, but a drawback is that certain foods (e.g. red meat) and medicines can also produce a positive result, so a special diet may be required prior to the test.
- Immunochemical faecal blood test (iFOBT or FIT): This more modern and specific method uses antibodies specific to human haemoglobin. It does not produce false-positive results due to food or other animal blood, and therefore does not require any dietary restrictions. It is particularly sensitive to detecting lower gastrointestinal bleeding (e.g. from the colon).
A positive faecal occult blood test is not a diagnosis in itself; it merely indicates the need for further investigations. Endoscopic examinations, such as a colonoscopy or a gastroscopy, are required to identify the exact location and cause of the bleeding.
What conditions can cause hidden bleeding?
There are a number of gastrointestinal conditions that may underlie hidden bleeding. These may be benign, but they could also be early signs of malignant tumours. It is important to take the symptoms seriously and consult a specialist to obtain an accurate diagnosis.
Common causes in the upper gastrointestinal tract
The upper gastrointestinal tract comprises the oesophagus, the stomach and the initial section of the small intestine (duodenum).
- Peptic ulcer: Gastric or duodenal ulcers are one of the most common causes of gastrointestinal bleeding. Infection with _Helicobacter pylori_ and the use of certain medicines, such as non-steroidal anti-inflammatory drugs (NSAIDs), may play a role in their development.
- Gastritis and oesophagitis: Inflammation of the stomach lining or the oesophagus can also lead to bleeding of varying severity. This may be caused by gastro-oesophageal reflux disease, alcohol or certain medicines.
- Angiomas (angiodysplasia): The abnormal, dilated blood vessels in the wall of the digestive tract are fragile and can bleed easily.
- Tumours: Both benign and malignant tumours of the oesophagus or stomach can cause occult bleeding. Iron-deficiency anaemia, which is a consequence of occult bleeding, may be one of the early signs of stomach cancer.
- Cameron lesion: A linear ulcer forming in the area of a hiatal hernia, which can also lead to chronic blood loss and iron deficiency.
Common causes in the lower digestive tract
The lower digestive tract comprises most of the small intestine, the large intestine, the rectum and the anus.
- Colonic polyps and colorectal cancer: Colonic polyps are benign growths that develop on the lining of the bowel and may become malignant over time. Both polyps and established bowel cancer often cause hidden bleeding. Screening is therefore crucial, as cancer can be prevented by the endoscopic removal of polyps.
- Diverticulosis: Small pouches (diverticula) that form in the wall of the large bowel may also bleed, although this more often causes sudden, visible bleeding.
- Inflammatory bowel diseases (IBD): Crohn’s disease and ulcerative colitis involve chronic inflammation, which can lead to damage to the intestinal lining and bleeding.
- Hemorrhoids (nodus haemorrhoidalis): Although haemorrhoids are usually bright red and cause visible bleeding on the surface of the stool, in some cases they may also cause minor, hidden bleeding.
- Rectal tear (fissura ani): An anal fissure is accompanied by pain and fresh bleeding, but chronic, minor fissures can also lead to hidden bleeding.
The role of lifestyle and prevention
Although many illnesses are caused by genetic or other factors beyond our control, we can do a great deal through our lifestyle to promote the health of our digestive system and reduce the risk of conditions leading to hidden bleeding.
The importance of nutrition
A balanced, fibre-rich diet is essential for maintaining the health of the large intestine.
- Increase your fibre intake: Eat plenty of vegetables, fruit, whole grains and pulses. Fibre helps to ensure regular bowel movements, preventing constipation, which in turn reduces the risk of haemorrhoids and diverticulosis.
- Cut down on your consumption of red and processed meats: Numerous studies confirm that excessive consumption of red meat and processed meat products (e.g. salami, sausages) increases the risk of colorectal cancer.
- Reduce your fat intake: A high-fat diet is also considered a risk factor. Opt for healthy fats, such as olive oil, nuts or avocados.
- Fluid consumption: Drinking an adequate amount of fluid – at least 2–2.5 litres a day (mainly water) – is essential for the proper digestion of fibre and for softening the stools.
Exercise and weight management
Regular physical activity stimulates bowel function and helps prevent constipation. It also helps maintain a healthy weight. Obesity has been shown to increase the risk of a number of digestive disorders, including acid reflux, hiatal hernia and bowel cancer. Aim for at least 150 minutes of moderate-intensity exercise a week, such as brisk walking, cycling or swimming.
Giving up harmful addictions
- Smoking: Smoking is harmful to the whole body and significantly increases the risk of stomach ulcers, Crohn’s disease and almost all cancers of the digestive system.
- Alcohol consumption: Excessive and regular alcohol consumption damages the lining of the oesophagus and stomach, can cause liver disease (cirrhosis) – which can also lead to severe gastrointestinal bleeding – and increases the risk of bowel cancer.
The risks associated with taking medication
Regular use of certain medicines, particularly non-steroidal anti-inflammatory drugs (NSAIDs, e.g. aspirin, ibuprofen, diclofenac), can damage the stomach lining and cause ulcers and bleeding. If you need to take such medicines, always consult your doctor about possible treatments to protect your stomach. Never exceed the dose recommended by your doctor!
When should you see a doctor? The steps involved in a medical examination
Hidden bleeding is dangerous because it can remain symptom-free for a long time. However, there are warning signs which, if present, make it essential to consult a gastroenterologist.
- Unexplained fatigue, weakness and pallor (signs of iron-deficiency anaemia)
- Changes in bowel habits (diarrhoea or constipation)
- Abdominal pain or discomfort
- Unexplained weight loss
- Positive faecal occult blood test
If you experience any such symptoms, do not hesitate to seek help. The first step in the assessment is usually a thorough medical history and a physical examination, followed by laboratory tests (complete blood count, iron levels).
Endoscopic examinations are required to pinpoint the source of the bleeding. The Endomedix Gastroenterology Centre offers modern, pain-free examinations:
- Colonoscopy (colonoscopy): An examination of the entire length of the large intestine, during which any polyps found can be removed immediately, thereby preventing the development of cancer. This examination is the „gold standard” in colorectal cancer screening.
- Gastroscopy (gastroscopy): Examination of the oesophagus, stomach and duodenum. It also allows for the taking of tissue samples and minor procedures.
- Capsule endoscopy: In cases where gastroscopy and colonoscopy fail to identify the source of the bleeding, a capsule containing a tiny, swallowable camera can help to examine the small intestine.
The next step is in your hands
Discovering hidden bleeding can be frightening, but it is important to know that early detection and appropriate treatment lead to a full recovery in most cases. A healthy lifestyle, a balanced diet and regular exercise can go a long way towards prevention, but the most important tools at our disposal are screening and regular check-ups with a specialist.
Don’t let fear or uncertainty hold you back! If you are experiencing the symptoms mentioned above, or are aged 45–50 and would like to take steps to look after your health, book an appointment for a screening test. The Endomedix Gastroenterology Centre Its experienced specialists and modern diagnostic procedures ensure the highest standard of care, all in a calm and patient-friendly environment. Take a step towards a worry-free future today!
