If rectal bleeding is accompanied by severe abdominal pain, vomiting that won’t stop, or dizziness and fainting, call 911 and seek medical help immediately.
Rectal bleeding is not normal and it can be upsetting. There are common reasons for bleeding such as hemorrhoids or a tear in the anal canal. Less common reasons include colon or rectal cancer, inflammatory bowel disease (IBD), diverticulosis, or ischemic colitis.
The medical term for bright-red blood in the stool is hematochezia. Whatever the potential cause, it is never normal and should always be investigated by a healthcare provider.
This article will address some of the reasons for rectal bleeding and how the cause might be diagnosed and treated.
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Symptoms of Rectal Bleeding
Rectal bleeding is when there is blood being passed out of the anus during a bowel movement on or in the stool, or by itself without stool. You might see it in the toilet bowl or on toilet paper after wiping.
The blood could be anything from bright red to black:
- Bright-red blood could be from something that is happening in the lower part of the digestive system, such as the colon, rectum, or anus.
- Dark blood, which may appear black, is older, so it may be coming from higher up in the digestive tract, such as from the small intestine, stomach, or esophagus (food tube).
The amount of blood is also helpful in figuring out where it might be coming from. A little bit of blood in the toilet can look like a lot when it hits the water. It’s important to get a look at it so that you can give the healthcare provider an idea of how much blood might be involved.
Causes of Rectal Bleeding
There are several causes of rectal bleeding.
Some of the more common reasons include:
- Anal fissure: The skin in the anal canal develops a tear, which can happen with large or hard bowel movements (constipation).
- Diverticular disease: Small outpouchings that develop in the lining of the colon can bleed.
- Hemorrhoids: The blood vessels in the anus or the rectum can become swollen and cause bleeding, pain, and itching.
- Trauma or foreign body: Anal sex or inserting objects in the anus may result in rectal bleeding.
- Ulcers: Ulcers (sores) in the lining of the esophagus (food tube), stomach, or anywhere along the small or large intestine may cause bleeding.
Some of the less common or rare reasons for rectal bleeding include:
- Anal fistula: A fistula is an abnormal tunnel between two organs or between an organ and the skin. A fistula that’s connected to the colon or the anus may cause bleeding.
- Anal cancer: This type of cancer is rare, and forms in the tissue of the anus.
- Colorectal cancer: Polyps that form in the colon or the rectum and become cancerous can cause rectal bleeding.
- Inflammatory bowel disease (Crohn’s disease or ulcerative colitis): IBD causes inflammation in various parts of the digestive tract, which could lead to bleeding.
- Ischemic colitis: When the blood vessels leading to the large intestine are blocked or narrowed, it could cause symptoms such as pain and bloody stools.
- Meckel’s diverticulum: This is a condition where an outpouching of the small intestine occurs. People are born with this condition (it is congenital) and it usually doesn’t cause symptoms, but it may, in some cases, cause bleeding.
- Pseudomembranous colitis: A bacterial infection may cause the lining of the colon to become inflamed and to bleed.
- Radiation enteritis: Treatment with radiation, such as for cancer, can cause inflammation in the intestine and bleeding.
- Solitary rectal ulcer syndrome: This is a rare condition that causes sores (ulcers) in the rectum, which may bleed.
What Medications Can Cause Rectal Bleeding?
Rectal bleeding can be caused by a tear in the anal canal that’s from straining to have a bowel movement or having hard stool (constipation). Many medications can lead to the development of constipation.
Some of them can include:
- Alpha agonists such as Catapres (clonidine)
- Anticholinergic agents like Atropen (atropine) and Ardane (trihexyphenidyl)
- Antihistamines such as Benadryl (diphenhydramine), Zyrtec (cetirizine), and Claritin (loratadine)
- Antipsychotics such as Versacloz (clozapine), Mellaril (thioridazine), and Thorazine (chlorpromazine)
- Antispasmodics such as Bentyl (dicyclomine)
- Beta-blockers such as Inderal (propranolol)
- Calcium channel blockers such as Norvasc (amlodipine), Cardizem (diltiazem), and Verelan (verapamil)
- Calcium and iron supplements, including antacids that contain calcium
- Histamine-2 receptor antagonists such as Pepcid (famotidine) and Tagamet HB (cimetidine)
- Opioid pain relievers such as Vicodin (acetaminophen and hydrocodone)
- Overactive bladder medications such as Ditropan (oxybutynin) and Detrol (tolterodine)
- Parkinson’s disease medications such as Sinemet (carbidopa and levodopa)
- Tricyclic antidepressants such as Elavil (amitriptyline) and Norpramin (desipramine)
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as Advil or Motrin (ibuprofen) and Aleve (naproxen) can cause intestinal ulcers that can lead to rectal bleeding.
There are other medications that can increase the risk of bleeding in the body. If there’s an ulcer or another issue going on in the digestive system, a medication that increases bleeding could cause it to bleed more than it normally would.
Some of these medications are:
- Anticoagulants (blood thinners) such as vitamin K antagonists, Coumadin (warfarin), or heparin
- Corticosteroids, such as prednisone
- Direct oral anticoagulants (DOAKs) such as Pradaxa (dabigatran), Eliquis (apixaban), Savaysa (edoxaban), and Bevyxxa (betrixaban)
- Platelet inhibitors such as Plavix (clopidogrel) or Effient (prasugrel)
How to Treat Rectal Bleeding
The treatment for rectal bleeding will depend on the cause. These treatments may be used for the most common causes:
- Anal fissure: An anal fissure might be treated at home with sitz baths (soaking in a shallow pan of warm water), increasing dietary fiber, and drinking more water. More serious tears might be treated with topical medications or, less commonly, surgery.
- Hemorrhoids: Hemorrhoids are often treated at home with over-the-counter (OTC) remedies such as medication creams and sitz baths. More troublesome or recurrent hemorrhoids may need treatment with prescription creams. In some cases, hemorrhoids may be treated with surgery.
- Ulcers: Treatment for ulcers might first be with OTC medications and/or prescription medications to block the production of stomach acids. Depending on the cause, antibiotics may be given. More serious ulcers or those that won’t heal with other methods might require surgery.
Treatments for less common causes include:
- Anal fistula: Fistulas that are associated with a disease, such as Crohn’s disease, will mean treating that disease effectively with diet, lifestyle changes, medication, and/or surgery. In some cases, the fistula itself will need surgery.
- Anal cancer: Anal cancer is usually treated with a combination of surgery, radiation, immunotherapy, and chemotherapy.
- Colorectal cancer: Colon cancer might be treated with a combination of radiation, chemotherapy, and surgery.
- Inflammatory bowel disease (Crohn’s disease or ulcerative colitis): IBD is a complicated disease and is treated with a combination of lifestyle changes, diet, medications, and, in some cases, surgery.
- Ischemic colitis: This type of colitis may be treated in the hospital with antibiotics, a liquid diet, intravenous fluids, pain management, and in some cases, surgery.
- Pseudomembranous colitis: For a bacterial infection, treatment with antibiotics might be used. If the infection keeps coming back, some providers may be able to arrange a fecal microbiota transplant (transferring stool from a healthy donor into the gastrointestinal, or GI, tract to balance the bacteria in it).
- Radiation enteritis: Inflammation from radiation treatment might be treated with antibiotics, nutritional therapy, and, in severe cases, surgery.
- Solitary rectal ulcer syndrome: Relief for constipation, laxatives, enemas, steroids, and bowel training might all be used to treat this type of ulcer. Rarely, surgery is used.
Complications and Risk Factors Associated With Rectal Bleeding
Rectal bleeding can lead to enough blood loss that a person develops anemia (a low number of healthy red blood cells). This can further be complicated by heavy menstrual periods or other problems in the body making enough red blood cells, such as a lack of important vitamins and minerals.
With severe blood loss, there is a risk of serious complications, including death. For bleeding that comes on suddenly and won’t stop, seek help in the emergency department right away.
Are There Tests to Diagnose the Cause of Rectal Bleeding?
In some cases, a test that can see the inside of the body is used to understand the cause of rectal bleeding. This could be a test to directly see inside the anus, rectum, and colon, or it could be an imaging test that gives a picture of the internal organs.
One or more of these tests might be used to find the cause of rectal bleeding:
- Anoscopy: In this test, a 3-inch long instrument called an anoscope is inserted by a physician into the anus to look at the anal canal and the rectum.
- Blood tests: Labs such as blood work won’t help pinpoint the cause of bleeding, but they can be used to see if there might be too many white blood cells (which could mean inflammation or infection), low iron levels, anemia, or clotting problems.
- Colonoscopy: In a colonoscopy, the entire colon is seen by inserting a thin tube with a light and a camera on the end. This test is normally done under sedation.
- Computerized tomography (CT) scan: This is a type of X-ray that produces cross-sectional images of the internal organs to look for abnormalities.
- Digital rectal exam: In this test, a healthcare provider quickly inserts a gloved, lubricated finger into the anus. The finger may come away with fluid such as blood or mucus on it, which helps start to narrow down the cause of the bleeding.
- Esophagogastroduodenoscopy: In this test, sometimes called an upper endoscopy, a tube with a light and a camera is inserted into the mouth and down into the stomach and the first part of the small intestine (duodenum).
- Flexible sigmoidoscopy: Similar to a colonoscopy, a thin tube with a camera and a light on the end is inserted into the anus and up through the rectum and the last part of the colon (called the sigmoid colon).
- Magnetic resonance imaging (MRI): This test uses strong magnets to make images of the inside of the abdomen to look for problem areas.
- Meckel’s scan: During this test, a compound containing a small amount of radiation is injected into a vein. The abdomen is monitored to see where the compound winds up, which could be the site of a Meckel’s diverticulum.
- Tagged red blood cell (RBC) scan: In this test, the person’s own blood is drawn, mixed with a small amount of a radioactive chemical, and then injected back into the body. A special camera is used to track those red blood cells and see where they are leaving the GI tract.
- Video capsule: In this test, a capsule with a camera in it is swallowed. Images from the capsule are sent wirelessly to a receiver.
- Visceral angiogram: In this test, a small tube is inserted into a blood vessel in the groin. Dye is put through the tube and tracked to see where it is leaving the blood vessel.
When to See a Healthcare Provider
Rectal bleeding is always a reason to have a touchpoint with a healthcare provider. For chronic conditions that cause bleeding during a flare-up, it is still important to get advice from a provider.
Bleeding from the rectum isn’t normal, and it is a sign that something is wrong. It could mean needing a diagnosis to find the cause of the bleeding or it could mean that a change is needed to better manage an already diagnosed condition.
Hemorrhoids are a common reason for bleeding. However, even hemorrhoids need to be diagnosed by looking at them. A diagnosis shouldn’t be made without a healthcare provider looking at the anus to see what the problem could be.
Seek emergency medical attention if rectal bleeding is accompanied by severe abdominal pain, vomiting, dizziness, or fainting,
Rectal bleeding is always a reason to talk to a healthcare provider. There are many possible causes of bleeding from the rectum, and because it is not ever normal, it’s a sign that there’s a problem that needs to be addressed.
A Word From Verywell
Seeing blood in the toilet bowl, on toilet paper, or on or in the stool is a shock. Even if it has happened before and you already know that you have hemorrhoids, IBD, or diverticular disease, it is still unsettling.
You may choose to ignore the blood or to hope that the bleeding stops on its own. But it may not happen that way, and catching a problem earlier rather than later can get you the right diagnosis and treatment.
It may help to remember that healthcare providers assist people with rectal bleeding every day, and they will not be shocked or surprised by what you tell them.
Frequently Asked Questions
What causes rectal bleeding?
There are many possible reasons for blood to be coming from the rectum but some of the most common conditions that cause bleeding are hemorrhoids, an anal tear or fissure, diverticular disease, or ulcers.
Bleeding from the rectum should always be discussed with a healthcare provider to determine the cause because it could result from more serious conditions.
How can I get rid of rectal bleeding?
If the bleeding is from a condition that can improve with home remedies, such as hemorrhoids, it might get better on its own. However, even if you have had hemorrhoids or an anal fissure before and think you have one again, you should still see a healthcare provider to be sure.
This will ensure you get the right treatment and that the bleeding is not from a cause that needs to be treated in a different way.
Can colon cancer cause rectal bleeding?
Colon cancer starts with an abnormal growth in the colon called a polyp. Polyps start out small and grow and may eventually start to bleed. The goal of colon cancer screening is to remove the polyp before it gets larger and has the opportunity to turn cancerous.