Blood in stool indicates bleeding somewhere within the gastrointestinal (GI) tract. This symptom can range from a minor issue to a serious underlying health condition. It always warrants medical evaluation to determine its origin and significance.
Appearance of Blood in Stool
The appearance of blood in stool provides clues about the bleeding’s origin. Bright red blood typically suggests bleeding from the lower GI tract, such as the colon, rectum, or anus. This color indicates the blood is fresh and has not traveled far.
Conversely, dark red or maroon blood often points to bleeding from higher up in the colon or small intestine. When stool appears black and tarry (melena), it usually signifies bleeding from the upper gastrointestinal tract, including the esophagus, stomach, or duodenum. The blood becomes dark and tarry as it is digested and interacts with chemicals during its journey.
Sometimes, blood in stool is not visible to the naked eye; this is referred to as occult or hidden blood. This type of bleeding can only be detected through specialized laboratory tests, such as a fecal occult blood test. Detecting occult blood can indicate subtle, ongoing bleeding that might otherwise go unnoticed.
Common Causes
Several common and often less serious conditions can lead to blood in stool. Hemorrhoids, which are swollen veins inside the rectum or around the anus, are a frequent cause of bleeding. These veins can bulge and bleed, especially due to straining during bowel movements.
Anal fissures are small tears in the lining of the anal canal, often resulting from passing hard or large stools. These tears can cause pain and bright red bleeding. Diverticulosis, a condition where small pouches called diverticula form in the colon wall, can also lead to bleeding if a blood vessel within a diverticulum erodes. Angiodysplasia involves fragile, abnormally formed blood vessels in the lining of the colon or small intestine that can rupture and bleed. Any instance of bleeding should still be evaluated by a healthcare professional.
More Serious Underlying Conditions
Blood in stool can signal more significant and potentially life-threatening conditions that require prompt medical attention. Inflammatory Bowel Disease (IBD), encompassing Crohn’s disease and ulcerative colitis, involves chronic inflammation of the digestive tract, which can lead to bleeding. Ulcerative colitis primarily affects the large intestine, while Crohn’s disease can impact any part of the GI tract.
Peptic ulcers, open sores that develop on the lining of the stomach or the first part of the small intestine (duodenum), can erode into blood vessels and cause significant bleeding, often resulting in black, tarry stools. Growths in the colon or rectum, known as polyps, can also bleed. Some polyps have the potential to become cancerous, making their early detection and removal important for preventing colorectal cancer.
Esophageal varices are enlarged veins in the esophagus, typically seen in individuals with severe liver disease, which can rupture and cause severe, acute bleeding. Ischemic colitis occurs when blood flow to a part of the large intestine is reduced, leading to inflammation and damage that can cause bleeding. These conditions highlight the importance of thorough medical evaluation.
When to Seek Medical Attention
Any observation of blood in stool, regardless of its appearance or quantity, warrants a consultation with a healthcare provider. While some causes are minor, others can be serious, and only a medical professional can accurately determine the underlying reason. Prompt medical attention is especially important if accompanied by other concerning symptoms.
Immediate medical evaluation is necessary for “red flag” symptoms like large amounts of blood, dizziness, fainting, or severe abdominal pain. Other concerning signs are persistent changes in bowel habits, unexplained weight loss, or fever alongside the bleeding. If blood is present with vomiting, this also indicates a need for urgent care. Self-diagnosis is not advisable, and professional medical advice is essential to ensure appropriate and timely management.
Diagnostic Approaches
When blood is present in stool, a healthcare provider will undertake a systematic approach to identify the source of bleeding. This process typically begins with a comprehensive medical history and a physical examination. This initial assessment helps gather information about the bleeding’s nature, associated symptoms, and relevant personal or family medical history.
Further investigation often includes stool tests, such as a fecal occult blood test, to detect occult blood. Blood tests may also be performed to check for anemia or other indicators of bleeding or inflammation. Endoscopic procedures are commonly used to visualize the digestive tract directly.
These include colonoscopy for the large intestine, sigmoidoscopy for the lower colon, and upper endoscopy for the esophagus, stomach, and duodenum. In some cases, imaging tests like CT scans, MRI, or angiography may be utilized to help pinpoint the location of bleeding, especially if endoscopic procedures are inconclusive. These diagnostic tools help medical professionals accurately diagnose the cause of blood in stool and guide appropriate treatment.