Common Causes of Blood in Stool

The presence of blood in stool, medically termed haematochezia or melena depending on the appearance, can be alarming and warrants careful medical evaluation. Blood in the stool can arise from various conditions ranging from benign to serious. Understanding the potential causes and their implications is important for timely diagnosis and appropriate treatment.
Common Causes
Blood in stool can be attributed to several common conditions, each with distinct characteristics and underlying mechanisms. Common causes include:
Haemorrhoids
Haemorrhoids, commonly known as piles, are swollen blood vessels in the lower rectum and anus. They can cause bright red blood in the stool or on toilet paper. Haemorrhoids may result from straining during bowel movements, prolonged sitting, chronic constipation, or pregnancy. Symptoms include pain, itching, and swelling around the anus. Treatment typically involves dietary changes, increased fibre intake, and over-the-counter remedies. In severe cases, medical procedures such as rubber band ligation or surgical removal may be necessary.
Anal Fissures
Anal fissures are small tears in the lining of the anus, often caused by passing hard or large stools. They can lead to pain and bleeding during bowel movements, with bright red blood typically noted. Symptoms include sharp pain during and after defecation, and visible cracks or tears around the anus. Treatment focuses on stool softeners, increased fibre and fluid intake, and topical anaesthetics or nitroglycerin ointment to reduce pain and promote healing. Chronic fissures may require surgical intervention.
Diverticular Disease
Diverticular disease encompasses diverticulosis and diverticulitis. Diverticulosis refers to the formation of small pouches (diverticula) in the colon wall, which may bleed. Diverticulitis occurs when these pouches become inflamed or infected. Blood in the stool due to diverticular disease is usually dark red or maroon. Symptoms include abdominal pain, fever, and changes in bowel habits. Management includes antibiotics for infection, dietary modifications, and in severe cases, surgery.
Inflammatory Bowel Disease (IBD)
IBD, including Crohn’s disease and ulcerative colitis, is a chronic condition characterised by inflammation of the gastrointestinal tract. Both conditions can cause bloody stools, with ulcerative colitis more commonly associated with rectal bleeding. Symptoms include abdominal pain, diarrhoea, weight loss, and fatigue. Diagnosis involves endoscopic evaluation, imaging studies, and laboratory tests. Treatment includes anti-inflammatory medications and immune system suppressors. Surgery may be required for severe cases.
Colorectal Polyps and Cancer
Colorectal polyps are benign growths on the inner lining of the colon or rectum, which can bleed and potentially progress to cancer. Colorectal cancer is a malignant tumour that often presents with blood in the stool, either visible or occult (hidden). Symptoms of colorectal cancer include changes in bowel habits, abdominal pain, weight loss, and fatigue. Screening methods such as colonoscopy are recommended for early detection and prevention. Treatment options include surgery, chemotherapy, and radiation therapy.
Gastrointestinal Infections
Infections caused by bacteria, viruses, or parasites can lead to gastrointestinal bleeding. Conditions such as bacterial gastroenteritis, viral enteritis, and parasitic infections like amoebiasis can cause bloody diarrhoea. Symptoms vary depending on the pathogen but generally include abdominal pain, fever, and diarrhoea. Diagnosis involves stool tests, blood tests, and sometimes imaging studies. Treatment depends on the specific infection and may include antibiotics, antiviral medications, or antiparasitic drugs.
Peptic Ulcers
Peptic ulcers are open sores that develop on the lining of the stomach, small intestine, or oesophagus due to the erosion by stomach acid. When these ulcers bleed, they can cause dark, tarry stools (melena). Symptoms include abdominal pain, bloating, nausea, and vomiting. Diagnosis is confirmed through endoscopy and tests for Helicobacter pylori infection. Treatment includes proton pump inhibitors, antibiotics (for H. pylori), and lifestyle modifications to reduce acid production.
Angiodysplasia
Angiodysplasia refers to abnormal blood vessels in the gastrointestinal tract, which can cause intermittent bleeding. This condition is more common in older adults and can lead to either visible or occult blood in the stool. Symptoms may be mild and include fatigue and anaemia due to chronic blood loss. Diagnosis is often made through endoscopy or imaging studies. Treatment may involve endoscopic procedures to cauterise bleeding vessels or medications to reduce bleeding risk.
When to Seek Medical Advice
It is essential to seek medical advice if you notice blood in your stool. While it may be something benign, such as haemorrhoids, it is important to rule out more serious conditions like colorectal cancer or inflammatory bowel disease. Consider consulting a gastroenterologist if you experience:
- Persistent Symptoms: Blood in stool that persists beyond a few days.
- Accompanying Symptoms: Abdominal pain, changes in bowel habits, weight loss, or fatigue.
- Risk Factors: A family history of gastrointestinal diseases or personal risk factors such as age over 50 years.
- Severity: Significant blood loss, black or tarry stools, or blood that is mixed within the stool.
Conclusion
Blood in the stool can be a symptom of various gastrointestinal conditions, ranging from benign to serious. Understanding the common causes are important for effective diagnosis and treatment. By adopting preventive measures and managing underlying conditions, people can reduce the risk of gastrointestinal bleeding and maintain optimal digestive health.
If you have any concerns or need personalised advice regarding blood in stool, don’t hesitate to reach out to our clinic. Our doctor is here to support you every step of the way.