Bright Red Blood in Stool
A bloody stool scares most people
Bright red blood in stool is alarming because it points to bleeding in the gut. However, not all red stools are caused by bleeding. The color can also come from food.
Foods Associated with Red Stool
Synthetic food colorants have become very popular nowadays. Our digestive enzymes can't completely break down some of these artificial dyes. Hence, a large portion of a red dye could be excreted intact, retaining its red color – staining your stool blood red.
Medical Conditions Associated with Bright Red Blood in Stool
Hematochezia is the medical term for bright red blood in stool. Rectorrhagia is when only blood is present without any bowel movement. Bleeding can occur anywhere in the GI (gastrointestinal) tract – in the mouth, esophagus, stomach, small bowel or large bowel.
Blood travelling through the gut turns black as it gets broken down by digestive juices. The farther away the bleeding is from the anus, the more likely blood from it will be broken down before excretion. A dark or black stool suggests bleeding high up the GI tract.
On the other hand, bright red blood in stool suggests bleeding in the lower part of the GI tract. The bleed in this case is closer to the anus. This does not leave sufficient time for blood to be broken down. Hence, the red maroon color of blood can be seen in the pieces of stool, in the toilet bowl or on the toilet paper. There are various conditions associated with GI bleeding. Some common ones are mentioned below.
- Anal fissures are tears in the lining of the anal canal. People with anal fissures are typically presented with sharp tearing pain and bleeding, often during defecation. The pain may last minutes to hours after defecation and can progress to burning and itching. Anal fissures commonly occur when a dry constipated stool scratches the wall of the anal canal. They sometimes heal on their own with out any real medication.
- Diverticulosis is a condition associated with the formation of small pouches in the lining of the colon. Doctors believe that blood vessels in these pouches may weaken and rupture causing bloody stools. Even though not proven, doctors say that people on low fibre diets are more prone to develop diverticulosis. Some symptoms of diverticulosis are linked to significant loss of blood. These include fatigue, shortness of breath and light-headedness.
- Ulcerative colitis is a disease that causes severe inflammation of the mucosa of the colon. According to researchers, some individuals are genetically predisposed to developing ulcerative colitis. Factors that can trigger the disease include microbes, autoimmune reactions and food allergies. The inflammatory process begins primarily in the rectum and can spread to other parts of the colon as the disease progresses. It can cause significant bleeding when it erodes down to blood vessels. Other symptoms are fever, diarrhea, fatigue and abdominal pain.
- Arterio-venous malformation (AVM), an abnormal collection of blood vessels can bleed intermittently. The bleeding is mainly because AVM-arteries connect directly to AVM-veins without passing through capillaries. The small size of capillaries reduces pressure as blood moves through to veins. Veins have thin walls and are generally not meant to withstand high pressures. AVM-veins can easily rupture causing bleeding.
- Hemorrhoids or Piles are swollen, inflamed veins inside or around the anus. They mainly result from the exertion of too much pressure on the anal region. This is common during pregnancy, constipation, prolonged sitting, heavy weightlifting or obesity. Rectal bleeding occurs when the hemorrhoid’s delicate surface is damaged – mainly from strain or irritation. Additional symptoms are rectorrhagia, redness, itching, rectal pain and discomfort.
- Colon cancer is cancer that starts in the colon. It is often discussed together with rectal cancer hence also referred to as colorectal cancer. Regular screening is recommended for high risk individuals in order to catch the cancer before it develops. It is highly curable at this stage. Key symptoms that suggest colon cancer include fatigue, anemia, weight loss, diarrhea, constipation, bloating and other changes in bowel habits. However, doctors have reported cases of colon cancer with no symptoms.
Bleeding from the Upper GI tract
Hemoglobin is the part of a red blood cell that contains iron. Unlike bleeding in the lower GI tract, blood from upper GI bleeding has enough time to interact with digestive juices. Iron in hemoglobin is oxidized as it passes through the gut. This results to a black, tarry stool known as melena.
Melena is worrisome because it indicates active bleeding from the upper gut. The color of blood in stool is a good indicator of the source of the bleeding. Some causes of melena are:
- Peptic ulcer – sore in the upper part of the small intestine.
- Esophagitis – inflammation of the esophagus.
- Gastritis – inflammation of the stomach lining.
- Esophageal varices – abnormal enlarged veins in the esophagus.
- Gastric varices – abnormal enlarged veins in the stomach.
- Mallory-weiss syndrome – tear in the mucus membrane at the stomach and the esophagus.
Situations that can lead to ‘false’ melenaClick thumbnail to view full-size
Fecal Occult Blood Test (FOBT)
It takes a significant amount of blood to be able to visually detect bleeding in one’s stool. If GI bleeding drops below a certain threshold, blood in stool may no longer be visible.
FOBT is a test performed to detect a small amount of blood in stool -- quantities of blood smaller than can be detected by the naked eye.
A small amount of fresh fecal sample is collected and smeared onto a small test card. The card is then sent to the lab. A special solution is added to the smear. The smear should turn blue in the presence of blood.
There is a stigma surrounding bowel disorders. Sufferers of bowel disorder are often embarrassed to talk about their bowel habits. Bright red blood in stool is a red flag but does not always point to a disease. However, it may be caused by a simpler condition such as anal fissures or a potentially life-threatening condition such as colorectal cancer.
Generally, bright red blood in your stool must prompt you to take a trip to your doctor to make sure it is not from a serious condition. A large amount of bleeding (including melena) can be potentially life-threatening. In this case, you should seek urgent medical attention.