Blood in the stool is the result of bleeding in your gastrointestinal (GI) tract. The GI tract includes organs like the stomach, small intestine, and large intestine (colon).
Seeing blood in your stool can be alarming. You may have heard blood in your stool can be a sign of cancer, but more often, bleeding is a symptom of a less serious condition.
Many conditions can cause it, including a bad case of diarrhea or constipation.
Symptoms of an emergency
There are multiple causes of blood in the stool.
Hemorrhoids are swollen veins inside the anus. They’re the most common cause of anal bleeding. Approximately
Hemorrhoids occur inside the rectum (the final part of the colon) and around the outer area of the anus.
The blood from hemorrhoids is usually bright red. Other symptoms can include anal itching and pain, but some people aren’t aware of the hemorrhoids until they bleed.
In certain cases, anal pain is due to a blood clot developing inside the hemorrhoid. This is known as a thrombosed hemorrhoid.
Anal fissures, sometimes called anal ulcers, are small tears in the lining of the anus. They’re caused by:
Anal fissures are very common in infants.
Alongside blood in your stool, you may also experience:
Inflammatory bowel disease (IBD)
These are autoimmune diseases, which cause your body to mistakenly attack itself. Your body sends white blood cells to parts of the digestive tract, where they release chemicals that cause damage, or inflammation, to the bowels.
Blood in the stool is a symptom of IBD, but you can also experience other symptoms, depending on the cause. These include:
- abdominal cramping or pain
- the urge to have a bowel movement when not needed
- weight loss
In addition to bleeding from the anus, you may also experience:
- a change in bowel habits
- stools that are very narrow, like a pencil
- abdominal pain or discomfort
- unexplained weight loss
Infection is another possible cause of blood in the stool. Infection that causes bloody diarrhea is also known as dysentery.
Dysentery has many bacterial causes and some parasitic causes. It’s very important that these infections are diagnosed early in the course of the illness so treatment can start as soon as possible.
Bacterial causes, which typically result in foodborne illnesses, include:
Entamoeba histolytica is one example of a parasitic cause of infection and dysentery.
In addition to bloody diarrhea, symptoms may include:
Other possible causes of blood in the stool include:
- colitis (inflamed colon)
- diverticulitis (inflamed digestive tract)
- gastritis (inflamed stomach lining)
- proctitis (inflamed rectum)
Conditions that may cause blood in the stool and blood in the vomit include:
- gastric ulcers
- duodenal ulcers
- esophageal varices
- Mallory Weiss tear, which occurs due to a tear in the lower esophagus from forceful vomiting or coughing
Gastric and duodenal ulcers are types of peptic ulcers. They’re commonly caused by:
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- Helicobacter pylori
- alcohol misuse
Ulcers can lead to black, tarry stools or bright red blood from the rectum, depending on how serious the bleeding is.
Esophageal varices are distended, or swollen, veins that can bleed in cases of severe liver disease. They’re usually caused by heavy alcohol use. They’re life threatening and require urgent medical attention.
People with esophageal varices may produce large volumes of bloody vomit as well as black, tarry diarrhea. Bright red blood from the rectum is also possible.
Blood when wiping is generally caused by bleeding in the lower GI tract, which includes the rectum and anus. This blood typically appears bright red on toilet paper.
Conditions that can cause blood when wiping include hemorrhoids and anal fissures.
Blood caused by conditions affecting other parts of the GI tract may be dark red or even black. This blood may only appear mixed in with the stool and may not be visible on the toilet paper.
Bright red blood in your stool usually indicates bleeding in your lower colon. It can indicate a mild or serious condition. Colorectal cancer is one of the most serious causes, but it only makes up about
Possible causes of rectal bleeding include:
A doctor will decide what tests you need based on your symptoms and medical history.
These tests may include a rectal exam or fecal occult blood test to look for abnormalities or blood in your colon. The rectal exam is a physical exam (which requires the doctor to touch you). The fecal occult blood test requires you to provide a stool sample.
Blood work, which includes a complete blood count, may be performed to see whether there’s evidence of anemia, inflammation, or infection. Anemia causes low hemoglobin, while inflammation and infection cause an elevated white blood cell count.
Stool samples, including stool cultures, can also be used to check for infection and determine the severity of disease.
Imaging studies, like an abdominal CT scan (with or without intravenous contrast), are commonly performed in people with blood in the stool. The scans can sometimes show the source of the bleed.
Your doctor may also perform an endoscopy to look for a blockage or abnormal growth. An endoscopy is a procedure that involves inserting a long tube with a camera on the end called an endoscope into your mouth or anus. Types of endoscopy include:
- Colonoscopy. During a colonoscopy, a long tube with a camera is inserted into your anus to examine your colon.
- Flexible sigmoidoscopy. A flexible sigmoidoscopy is similar to a colonoscopy but only examines your lower colon.
- Esophagogastroduodenoscopy (EGD). During an EGD test, a doctor puts a long tube with a camera down your throat to examine your esophagus, stomach, and upper part of your small intestines.
- Enteroscopy. During an enteroscopy, a doctor inserts a long tube with a camera into your anus or mouth. When the camera reaches the area your doctor wants to examine, a balloon inflates to allow for a better view.
Another procedure your doctor may want to perform is a gastrointestinal bleeding scan, a form of radionuclide scanning. This procedure involves injecting a small amount of the radioactive metal technetium-99m into your blood. A special gamma camera takes pictures of your digestive tract to search for bleeding areas.
Treatment will depend on the cause of blood in your stool.
Treatment for hemorrhoids
Lifestyle changes can help ease or even prevent hemorrhoids.
Hemorrhoid prevention tips
Over-the-counter (OTC) ointments and hydrocortisone suppositories can also provide relief.
Persistent hemorrhoids may protrude from the anus, especially with frequent constipation or straining. Wash the area with warm water after a bowel movement to help them shrink faster.
If your hemorrhoids are large, a doctor can shrink or remove them surgically.
Treatment for anal fissures
Anal fissures usually heal without treatment, or can be treated at home. Take the steps below:
- Drink more fluids and eat more fiber, like fruits and vegetables.
- Try fiber supplements if changing your diet hasn’t helped.
- Take sitz baths to increase blood flow to the area and relax the anal muscles.
- Use topical pain relievers like lidocaine (Lidoderm) to ease discomfort.
- Try OTC laxatives to encourage bowel movement.
See a doctor if your symptoms don’t get better with treatment after 2 weeks. Your doctor can help make a more accurate diagnosis to make sure you get the right treatment.
Treatment for IBD
There’s no cure for most types of IBD, but treatment can help you manage the condition. Treatment depends on the specific diagnosis and can involve:
- anti-inflammatory drugs to ease the digestive tract
- immunosuppressants to block the immune system from attacking your body
- biologic drugs to prevent certain proteins from causing inflammation
Optimizing nutrition is also a major factor, as some people may find that different foods trigger their IBD symptoms.
When medications aren’t working to manage severe cases of IBD, your doctor may recommend surgery to remove affected portions of your colon.
In general, IBD requires careful monitoring and medical care. Maintaining a nutrient-rich diet, exercising regularly, and working closely with a gastroenterologist can help prevent progression of IBD or a relapse.
Treatment for colorectal cancer
Talk with your doctor if you believe you have colorectal cancer. They can help determine a diagnosis, what stage the cancer is in if you do have cancer, and the right treatment for you. The earlier you get treatment, the better your outcome.
Diagnosis is first made with a biopsy, usually with colonoscopy or flexible sigmoidoscopy depending on the location of the tumor. Afterward, imaging is done so your doctor can see the extent of the disease before they make a plan for surgery, chemotherapy or radiation.
Treatment for infection
Management includes oral rehydration, if possible. If a person is clinically dehydrated, they should receive intravenous fluid administration instead.
Depending on the severity of a bacterial cause, antibiotics may be needed. They shorten the duration of illness and the time period during which the infection can potentially be transmitted.
Management of parasitic causes includes antiparasitic medications.
See a doctor if you have:
- pain that worsens or persists
- blood that’s dark or thick-looking
- black and sticky stool, which can indicate digested blood
- symptoms that don’t get better within 2 weeks
Seek immediate medical care if you feel dizzy, weak, or confused, or if you’re bleeding a lot.