What are the causes of minor rectal bleeding (Rectal Bleeding)?

From the Guidelines

Minor rectal bleeding is most commonly caused by hemorrhoids or anal fissures, but can also be a symptom of more serious conditions such as inflammatory bowel disease or colorectal cancer, and therefore, requires a thorough evaluation by a healthcare provider. The causes of minor rectal bleeding can be diverse, and a precise diagnosis is essential to rule out other pathology. According to the American Gastroenterological Association technical review on the diagnosis and treatment of hemorrhoids 1, bleeding is the most common presenting symptom of hemorrhoids, and the blood is typically bright red. However, darker blood and blood mixed in the stool suggest a more proximal source of bleeding.

Common Causes of Minor Rectal Bleeding

• Hemorrhoids: Hemorrhoids are a common cause of minor rectal bleeding, and they can be internal or external 1.
• Anal fissures: Anal fissures can also cause minor rectal bleeding, especially if they are deep or chronic 1.
• Inflammatory bowel disease: Inflammatory bowel disease, such as Crohn's disease or ulcerative colitis, can cause rectal bleeding, and it is essential to rule out this condition in patients with persistent or recurrent bleeding 1.
• Colorectal cancer: Colorectal cancer is a more serious condition that can cause rectal bleeding, and it is essential to evaluate patients with rectal bleeding for this condition, especially if they have risk factors such as a family history or a history of polyps 1.

Evaluation and Management

The evaluation of minor rectal bleeding should include a thorough medical history, physical examination, and laboratory tests to rule out other causes of bleeding 1. The American Society for Gastrointestinal Endoscopy and the Society for Surgery of the Alimentary Tract recommend a minimum of anoscopy and flexible sigmoidoscopy for bright-red rectal bleeding 1. Complete colonic evaluation by colonoscopy or air-contrast barium enema is indicated when the bleeding is atypical for hemorrhoids, when no source is evident on anorectal examination, or when the patient has significant risk factors for colonic neoplasia 1.

In patients with suspected bleeding hemorrhoids, it is essential to collect a focused medical history and perform a complete physical examination, including a digital rectal examination, to rule out other causes of lower gastrointestinal bleeding 1. The diagnostic workup should also include laboratory tests, such as a complete blood count, serum electrolytes, blood urea nitrogen, creatinine, and coagulation assessment, to determine the severity of the bleeding and to correctly stratify the risk for the patient 1.

Proper evaluation and management of minor rectal bleeding are crucial to prevent morbidity, mortality, and to improve the quality of life of patients. If bleeding continues beyond a week, worsens, or is accompanied by pain, fever, or changes in bowel habits, patients should seek immediate medical attention. Initial management can include increasing dietary fiber, drinking plenty of water, and using over-the-counter remedies like hydrocortisone creams or psyllium fiber supplements, but these treatments should only be used under the guidance of a healthcare provider 1.

From the Research

Causes of Minor Rectal Bleeding

The causes of minor rectal bleeding can range from benign to life-threatening conditions. Some of the possible causes include:

• Haemorrhoids, which are the most common cause of rectal bleeding 2
• Diverticulosis and vascular dysplasia, which account for 30-50% of colonic bleeding 3
• Inflammatory bowel disease and ischemic colitis, which account for 5-15% of colonic bleeding 3
• Anal fissures, which can be diagnosed and treated using a structured patient history and basic proctological diagnostic assessment 4
• Proctitis, which can be associated with chronic inflammatory bowel disease, prolapse-induced, radiogenic, ischemic, infectious types, and proctitis associated with sexually transmitted diseases 4
• Rectal cancer, which must be excluded as a cause of rectal bleeding 2, 4

Differential Diagnosis

The differential diagnosis of rectal bleeding can be based on risk factors such as age and comorbid conditions 5. For example:

• Patients over 40 years old presenting with rectal bleeding require colonoscopy to screen for and treat premalignant polyps and colorectal cancer 2
• Patients with moderate to severe rectal bleeding may require further investigation to determine the source of bleeding, which can be located anywhere along the gastrointestinal tract 3

Evaluation and Management

The evaluation and management of rectal bleeding require a systematic approach, including:

• A thorough patient history and physical examination 6
• Basic proctological diagnostic assessment, such as anoscopy and sigmoidoscopy 4
• Laboratory tests, such as complete blood count and stool tests 5
• Imaging studies, such as colonoscopy and CT scan 5
• Treatment options, including medical and surgical management, depending on the underlying cause of rectal bleeding 5, 4