Why Do I See Blood in My Stool? Understanding the Causes and What To Do

Discovering blood in your stool can be alarming, and it’s a topic many find uncomfortable to discuss. While it’s natural to feel embarrassed or worried, especially about serious conditions like cancer, it’s crucial to understand that blood in the stool can stem from various causes, many of which are treatable. It’s a signal from your body that warrants attention and a conversation with a healthcare professional.

Common Reasons for Blood in Your Stool

The appearance of blood in your stool isn’t always a sign of a life-threatening condition, but it should never be ignored. Several factors can contribute to this symptom, ranging from minor and easily managed issues to more significant health concerns. Here are some of the common reasons why you might find blood in your stool:

Hemorrhoids: These are swollen veins in the rectum and anus, much like varicose veins, and are a very frequent cause of rectal bleeding. They can be internal or external and are often associated with straining during bowel movements, chronic constipation, or diarrhea.
Anal Fissures: These are small tears in the lining of the anus, typically caused by passing hard stools. Anal fissures can be quite painful and often result in bright red blood, usually noticed on toilet paper after wiping.
Rectal Prolapse: This condition occurs when the rectum, the final section of the large intestine, slips out of its normal position and protrudes through the anus. While less common, it can lead to bleeding and discomfort.
Rectal Polyps: These are growths on the lining of the rectum and colon. While many are benign, some types of polyps can be precancerous or cancerous. Polyps can bleed, and this blood may appear in your stool.
Rectal Ulcers: Sores or breaks in the lining of the rectum, known as ulcers, can be caused by various factors including infections, inflammatory conditions, or certain medications. These ulcers can bleed and cause pain.
Injury to the Colorectal Mucosa: The mucosa is the lining tissue of the colon and rectum. This delicate tissue can be injured by various factors, leading to bleeding. Even minor trauma can sometimes result in blood in the stool.
Diverticular Bleeding: Diverticula are small pouches that can form in the wall of the colon. Sometimes these pouches can bleed, leading to a condition called diverticular bleeding, which can manifest as blood in the stool.
Inflammatory Bowel Diseases (IBD): Conditions like Ulcerative Colitis and Crohn’s Disease are chronic inflammatory conditions that affect the digestive tract. Inflammation and ulceration in the colon and rectum, common in IBD, can cause significant bleeding.
Colorectal Cancer: While it’s a major concern, colorectal cancer is one of the more serious but less common causes of blood in the stool, especially in younger individuals. Bleeding from tumors can be a sign of colorectal cancer, highlighting the importance of getting checked.

It’s important to remember that while some of these conditions, like hemorrhoids and anal fissures, are often related to lifestyle factors such as diet and bowel habits, any instance of blood in the stool requires proper diagnosis to rule out more serious underlying issues.

How to Determine the Cause of Blood in Your Stool

If you notice blood in your stool, the most crucial step is to seek medical advice. Self-diagnosis can be risky, and accurate identification of the cause requires professional evaluation. Doctors use a straightforward approach to investigate the source of bleeding, typically involving:

Rectal Exam: This is often the initial step in diagnosing rectal bleeding. A physical examination of the anus and rectum allows the doctor to check for hemorrhoids, anal fissures, and rectal prolapse. The doctor may also perform a digital rectal exam, inserting a gloved, lubricated finger into the rectum to feel for any abnormalities, such as polyps or masses.
Colonoscopy: A colonoscopy is the gold standard for examining the entire colon and rectum. This procedure involves using a long, flexible tube with a camera attached to it. The colonoscope is inserted into the anus and gently advanced through the colon, allowing the doctor to visualize the lining of the large intestine on a monitor. A colonoscopy can detect polyps, tumors, inflammation, and other abnormalities. It’s usually performed under sedation to minimize discomfort. Preparation for a colonoscopy involves cleaning out the colon, typically by drinking a laxative solution, to ensure a clear view.

Given the increasing incidence of colorectal cancer in younger populations, many physicians recommend a colonoscopy to thoroughly investigate blood in the stool, especially for individuals over 45 or those with risk factors. While the thought of a colonoscopy might be daunting, it’s a relatively quick and safe procedure with a short recovery time. Regular colonoscopies are also recommended as a preventative measure for colorectal cancer screening, typically starting at age 45 and repeated every 10 years for those at average risk. If you’re experiencing blood in your stool, undergoing a colonoscopy is a proactive step towards ensuring your health and ruling out serious conditions.

Deciphering the Color and Appearance of Blood in Your Stool

The characteristics of blood in your stool can provide valuable clues about its potential origin within your digestive system. The digestive tract is extensive, spanning approximately 30 feet, and the appearance of blood can vary depending on where the bleeding is occurring. Paying attention to the color and form of the blood can help your doctor narrow down the possible causes.

Bright Red Blood: Bright red blood in your stool typically indicates bleeding that is occurring closer to the anus and rectum. Common sources of bright red blood include hemorrhoids, anal fissures, diverticular bleeding in the lower colon, and sometimes polyps or tumors located in the lower rectum. If you notice bright red blood, especially if it’s on the surface of the stool or on the toilet paper, it’s likely originating from the lower part of your digestive tract.
Dark Red or Maroon Blood: Darker red or maroon-colored blood suggests that the bleeding is originating from higher up in the colon or the upper part of the digestive tract. As blood travels further through the digestive system, it becomes darker due to digestion. Bleeding from the upper colon or small intestine can present with this darker hue.
Black or Tarry Stool (Melena): Stool that appears black and tarry, often described as having a sticky consistency, is a significant indicator of bleeding from the upper gastrointestinal (GI) tract, which includes the esophagus, stomach, and the first part of the small intestine (duodenum). The dark, tarry appearance is a result of blood being digested as it moves through the GI tract. Melena can be a sign of serious conditions like stomach ulcers or bleeding in the small intestine and requires prompt medical attention.
Blood on Toilet Paper Only: If you primarily notice blood only when wiping, and not mixed in with the stool itself, this is frequently associated with hemorrhoids or anal fissures. These conditions are located very close to the anal opening, resulting in blood being deposited on the toilet paper. While often less serious, it still warrants medical confirmation to rule out other causes.
Microscopic Blood: In some cases, bleeding may be slow and minimal, resulting in microscopic amounts of blood in the stool. This blood may not be visible to the naked eye or might only cause a slight darkening of the stool. Slowly bleeding tumors or polyps higher up in the colon can sometimes present in this way. Fecal occult blood tests (FOBT) or fecal immunochemical tests (FIT) are used to detect microscopic blood in the stool, often as part of routine colorectal cancer screening.

Regardless of the color or appearance of blood, it’s essential to report it to your doctor. Even if the bleeding seems minor or intermittent, it’s a symptom that needs to be evaluated to determine the underlying cause and ensure appropriate management.

When Blood in Stool Might Be More Worrisome

While any instance of blood in your stool should be checked by a doctor, certain situations and accompanying symptoms can make it more concerning and necessitate prompt medical attention.

Persistent or Recurring Blood is a Red Flag

It’s a common misconception that if blood in the stool comes and goes, it’s not a serious issue. However, intermittent bleeding should not be dismissed. Some conditions, including cancers, can bleed intermittently. The bleeding may stop and start, leading to a false sense of reassurance. Therefore, any recurring or persistent blood in your stool, even if it’s not present every time you have a bowel movement, should be evaluated to rule out serious underlying causes. Don’t delay seeking medical advice simply because the bleeding is not constant.

Accompanying Symptoms to Watch Out For

In addition to the presence of blood in your stool, be vigilant for other accompanying symptoms that could indicate a more serious underlying condition. These “red flag” symptoms, when combined with rectal bleeding, require immediate medical attention:

Anemia and/or Feeling Light-Headed: Significant blood loss can lead to anemia, a condition characterized by a deficiency of red blood cells or hemoglobin in the blood. Anemia can cause fatigue, weakness, and lightheadedness, especially when standing up quickly. If you experience these symptoms along with blood in your stool, it could indicate substantial blood loss.
Chest Pain and Shortness of Breath: In severe cases of anemia due to blood loss, the body may not be getting enough oxygen. This can manifest as chest pain and shortness of breath, symptoms that warrant immediate medical evaluation.
Pain in Your Abdomen, Pelvis, or Rectum: Persistent or severe pain in the abdomen, pelvis, or rectum, especially when associated with blood in the stool, can be a sign of various gastrointestinal issues, including inflammatory conditions, infections, or even cancer.
Fevers: Unexplained fevers, particularly when accompanied by blood in the stool and abdominal pain, can indicate an infection or inflammatory process in the digestive tract. Certain cancers can also sometimes cause fevers.
Nausea and Vomiting: Persistent nausea and vomiting, especially if accompanied by blood in the stool, can be indicative of gastrointestinal disorders that require medical attention.
Unexplained Weight Loss: Significant and unintentional weight loss, especially when combined with changes in bowel habits or blood in the stool, is a concerning symptom that could be associated with serious conditions like cancer or chronic inflammatory diseases.

If you experience any of these symptoms in conjunction with blood in your stool, it’s crucial to seek prompt medical evaluation. These symptoms can provide important clues about the underlying cause of the bleeding and help guide appropriate diagnosis and treatment.

Listen to Your Body

Your body often provides early warning signs when something is amiss. Symptoms like blood in your stool are your body’s way of signaling that attention is needed. It’s crucial to listen to these signals and not ignore them, even if they seem minor or come and go. Many health problems can exist and develop even before noticeable symptoms appear. Therefore, when symptoms do arise, they should be taken seriously.

Even in the absence of any symptoms, regular health screenings, such as colonoscopies for colorectal cancer, are recommended, especially as you age. However, if you observe blood in your stool at any age, it’s a clear indication that something is happening within your digestive system that needs to be investigated. Don’t hesitate to reach out to your doctor to discuss your concerns and get the necessary evaluation. Early detection and diagnosis are key to effective management and treatment of any underlying condition.