- 7/24 Live Call Center
Last Updated on November 26, 2025 by Bilal Hasdemir
Seeing blood in your stool can be scary, and it’s hard to know why. Many things can cause rectal bleeding. But, if your stool looks different and you have pain, it might be serious.Discover bowel cancer stool colour and what blood in stool may indicate about your health.
Blood in stool looks bright red if it’s from the lower part of your colon. It’s dark, black, or tarry if it’s from higher up. At Liv Hospital, they focus on finding problems early. They use advanced tests to help patients get better.
Bowel cancer, also known as colorectal cancer, is a complex condition. It is influenced by genetics and the environment. It starts with abnormal cell growth in the colon or rectum, which can lead to tumors.
Bowel cancer often begins as a polyp in the colon or rectum. Over time, some polyps can turn cancerous. The growth of bowel cancer is linked to genetic mutations, which can be inherited or caused by the environment.
In the United States, bowel cancer is a common cancer type. Risk factors include age, family history of colorectal cancer, and genetic conditions like Lynch syndrome. Lifestyle factors, such as diet and exercise, also affect risk.
| Risk Factor | Description |
| Age | Risk increases significantly after the age of 50 |
| Family History | Having a first-degree relative with colorectal cancer increases risk |
| Genetic Conditions | Conditions like Lynch syndrome increase the risk of bowel cancer |
Early detection of bowel cancer greatly improves treatment outcomes. Screening tests can find polyps before they turn cancerous or detect cancer early when it’s more treatable.
Early detection is key for managing and treating bowel cancer effectively. Regular screenings are advised for those over 45 or with a higher risk.
Blood in stool from bowel cancer can look different. It can be bright red or dark and tarry. The color and texture of the blood can tell us a lot about where the bleeding is coming from. It might even suggest bowel cancer.
Bright red blood usually means bleeding from the lower colon or rectum. This is often linked to bowel cancer, mainly when the tumor is in the distal parts of the colon or rectum. The blood looks bright red because it’s fresh and hasn’t been digested much.
Dark or black tarry stool, or melena, usually means bleeding from the upper GI tract. But in bowel cancer, it can also happen if there’s a lot of bleeding from a tumor on the right side of the colon. The dark color comes from the blood being digested and partially broken down in the intestines.
Maroon-colored blood is between bright red and black tarry stool. It usually means bleeding from the right side of the colon or the small intestine. In bowel cancer, maroon stool can happen if there’s a lot of bleeding from a tumor in these areas.
Occult bleeding is blood in stool that you can’t see with your eyes. You need a fecal occult blood test (FOBT) to find it. It can be an early sign of bowel cancer, even if the bleeding is small and not noticeable.
Knowing how blood in stool can look can help people spot signs of bowel cancer. If you notice any unusual changes in your stool, it’s important to see a doctor.
Stool color and frequency can change with bowel cancer, giving clues for diagnosis. It’s key to know these signs to spot bowel cancer symptoms early.
Stool color usually ranges from light to dark brown. But, bowel cancer can change this. Bright red blood might mean bleeding from a tumor in the lower colon or rectum. Dark or black tarry stools (melena) suggest bleeding from higher up.
A study in the Journal of Clinical Gastroenterology found that melena is linked to a higher risk of cancers like bowel cancer.
The bowel’s tumor location affects stool appearance. Tumors in the lower colon or rectum cause visible bleeding. Tumors higher up lead to occult bleeding, which isn’t seen.
| Tumor Location | Stool Appearance |
| Lower Colon/Rectum | Bright Red Blood |
| Upper Colon | Dark or Black Tarry Stools |
| Any Location | Occult Bleeding (not visible) |
Bowel cancer can also change stool consistency and frequency. You might have diarrhea, constipation, or feel like you’re not fully emptying your bowels. These changes can happen if the tumor blocks the bowel or changes how it moves.
“Changes in bowel habits, including frequency and consistency of stool, are among the key symptoms that may indicate bowel cancer.” – American Cancer Society
Mucus in stool can also hint at bowel cancer. Mucus is a protective fluid in the bowel. More mucus can mean a tumor is present.
In summary, changes in stool color, consistency, frequency, and mucus can signal bowel cancer. Spotting these signs early is vital for treatment.
Bowel cancer can cause noticeable changes in stool shape and consistency. These changes happen because the tumor affects the colon or rectum. This disrupts the bowel’s normal function.
One key change is thin, ribbon-like, or pencil-shaped stools. This happens when a tumor narrows the colon. It restricts stool passage, making it thinner and longer than usual.
Bowel cancer can also change bowel habits. It can cause either diarrhea or constipation. These changes might happen because the tumor partially blocks the bowel or because of the body’s reaction to the cancer.
Some people with bowel cancer feel like they didn’t fully empty their bowels after using the bathroom. This feeling can be uncomfortable. It might be because a tumor is blocking the normal passage of stool.
| Stool Characteristic | Possible Cause |
| Thin, ribbon-like stools | Narrowing of the colon by a tumor |
| Diarrhea or constipation | Partial bowel obstruction or body’s response to cancer |
| Incomplete evacuation sensation | Tumor obstructing normal stool passage |
It’s important to notice these changes and see a healthcare professional if they last or if you have other symptoms that worry you.
It’s important to know about the pain and discomfort of bowel cancer. This knowledge helps in early detection and treatment. Symptoms can vary based on the tumor’s location, size, and stage.
Lower back pain is linked to bowel cancer, mainly when the tumor is in the lower colon or rectum. This pain happens because the tumor presses on nerves or surrounding structures.
Abdominal pain is a common sign of bowel cancer. This pain can be sharp or dull and may change in intensity. Pelvic pain also occurs, often when cancer spreads to the pelvic area.
Pain during bowel movements is a key sign of bowel cancer. This pain often comes from a tumor in the rectum or lower colon. It can cause discomfort or pain when you have a bowel movement.
Other signs of bowel cancer include feeling like you haven’t fully emptied your bowels. You might also notice changes in stool consistency or see blood in your stool.
| Pain/Discomfort Type | Description | Possible Cause |
| Lower Back Pain | Persistent pain in the lower back region | Tumor pressing on nerves or surrounding structures |
| Abdominal Pain | Localized or diffuse pain in the abdominal area | Tumor growth or bowel obstruction |
| Pain during Bowel Movements | Pain or discomfort while passing stools | Tumor in the rectum or lower colon |
Blood in stool is a key symptom that, when paired with other signs, may point to bowel cancer. It’s important to notice these symptoms early for timely treatment.
Unexplained weight loss and constant tiredness are common in bowel cancer patients. These happen because the body can’t absorb nutrients well and the cancer uses a lot of energy. Significant weight loss without diet or exercise changes is a red flag for doctors.
Nausea and vomiting can also be signs of bowel cancer. This is often due to a tumor blocking the bowel or messing with digestion. These symptoms can cause dehydration and imbalance of electrolytes if not treated.
Anemia is a complication of bowel cancer due to ongoing blood loss. Symptoms include pale skin, weakness, and shortness of breath. Treating anemia is key to improving life quality.
In advanced stages, bowel cancer can cause bowel obstruction. This leads to severe stomach pain, constipation, and vomiting. These symptoms need quick medical help to avoid serious issues like bowel perforation.
Seeing blood in stool with these symptoms means it’s time for a detailed medical check-up. Catching bowel cancer early can greatly improve treatment success.
Many gastrointestinal issues can look like bowel cancer, making diagnosis tricky. It’s key to know how to tell bowel cancer apart from other diseases with similar symptoms.
Hemorrhoids often cause rectal bleeding, which can be mistaken for bowel cancer. But, the bleeding’s color and timing can tell us a lot. Hemorrhoids usually cause bright red blood right after you poop. Bowel cancer bleeding can be different in color and mixed with stool.
Inflammatory bowel disease (IBD) can have symptoms like bowel cancer, like diarrhea and pain. But, IBD has ups and downs, and symptoms can spread out more.
Diverticular disease can also cause bleeding, like bowel cancer. The bleeding is sudden and painless, and it can be a lot. While many older adults have diverticula, not all of them bleed.
Black stools can be scary and often mean bowel cancer. But, there are many reasons for it that aren’t cancer, like iron pills or certain foods like black licorice.
| Condition | Common Symptoms | Differentiating Features |
| Hemorrhoids | Bright red bleeding during defecation | Bleeding is typically not mixed with stool |
| Inflammatory Bowel Disease | Diarrhea, abdominal pain, weight loss | Periods of remission and flare-ups |
| Diverticular Disease | Sudden, painless rectal bleeding | Bleeding is usually significant |
| Bowel Cancer | Varied bleeding, changes in stool | Bleeding may be mixed with stool, other systemic symptoms |
Certain symptoms need quick medical help, and knowing them can greatly improve bowel cancer outcomes. If you notice any red flag symptoms, it’s important to see a doctor right away.
Significant rectal bleeding, severe abdominal pain, or unexplained weight loss are urgent signs. Severe bleeding or persistent abdominal pain are serious and could mean advanced bowel cancer.
Before your doctor’s visit, gather details about your symptoms. Note when they started, how often they happen, and what might make them better or worse. A symptom diary can be very helpful.
Screening advice changes with age and risk. Usually, people over 45 should start screening. If you have a family history or other risks, you might need to start sooner. Talk to your doctor about the right screening plan for you.
Your doctor might suggest tests like a colonoscopy, stool test, or CT scan if you have symptoms or need screening. These tests help find and understand bowel cancer.
Being proactive about your health and knowing when to get medical help can greatly improve bowel cancer outcomes. If you’re worried about symptoms, don’t wait to talk to your healthcare provider.
Knowing the signs of bowel cancer is key to catching it early. Changes in stool color, consistency, and blood can help. Early treatment greatly improves survival and treatment success.
People can help by knowing their body’s normal and reporting any changes. Regular check-ups are important for catching cancer early. By acting fast and getting medical help, you can get better treatment and health.
Being informed and watchful helps you control your health. This way, you can help improve bowel cancer outcomes by catching it early and treating it well.
Blood from colon cancer can look bright red, dark, or black. It can also be maroon-colored. The color depends on where the tumor is in the colon.
Yes, bowel cancer can cause back pain. This is more common if the tumor is in the lower colon or rectum. The pain might spread to the back because of the tumor’s location.
Symptoms of bowel cancer include unexplained weight loss and fatigue. You might also feel nauseous or vomit. Anemia and changes in bowel habits are common too. Some people experience abdominal or pelvic pain.
Doctors use tests like colonoscopy and stool tests to find bowel cancer. Imaging studies and biopsies help confirm the diagnosis.
Risk factors include age and family history. Genetic predisposition and inflammatory bowel disease also play a role. Lifestyle choices, like diet and exercise, are important too.
Yes, hemorrhoids can look like bowel cancer because they cause similar symptoms. But, hemorrhoids are usually not cancer. A proper diagnosis is needed to know the cause.
Occult blood is blood in stool that you can’t see. It can be found through stool tests. Finding occult blood, along with other symptoms, might mean you have bowel cancer.
Keep a record of your symptoms and when they started. Talk about your medical and family history. Be ready to discuss any screening tests you’ve had.
Screening for bowel cancer starts at age 45 for most people. Those at higher risk might need to start earlier or have more tests.
Yes, changes in stool shape, like thin stools, can be a sign of bowel cancer. Look out for these changes, along with blood in stool or pain.
American Cancer Society. (2023). Rectal cancer surgery. Cancer.org. https://www.cancer.org/cancer/types/colon-rectal-cancer/treating/rectal-surgery.html
