Rectal Bleeding: Causes for Concern

Rectal bleeding, also called gastrointestinal bleeding, may or may not be visible. When it is, it’s scary, and you probably wonder if you should see the doctor.

Some types of rectal bleeding aren’t serious, but it’s always best to find out. This post discusses what rectal bleeding is, what can cause it, symptoms, diagnosis, and treatment. It also lets you know when to go to the emergency room.

An Overview of Rectal Bleeding

Rectal or gastrointestinal bleeding is bleeding anywhere in the digestive tract from the esophagus to the rectum. It may be from a small area, like an ulcer in your stomach lining. Or it can be from a larger area, like if your colon becomes inflamed. 

Rectal bleeding can signal a variety of medical conditions, both mild and severe. You might find blood on the toilet paper after wiping, in the toilet bowl, or on the stool (poop). It might even be different colors, from bright red to black depending on where the bleeding originates and what happens to it.

It might not even be blood, depending on what you ate. Some foods can turn your stool into alarming colors. Just keep in mind whether you had beets for dinner yesterday before panicking.

What Causes Rectal Bleeding

We mentioned two examples of rectal bleeding causes above –  ulcers and colon inflammation.

The blood you find on the toilet paper doesn’t always mean it’s serious. One of the most common reasons for rectal bleeding is hemorrhoids. While they can be painful, they aren’t serious. 

On the other hand, it could be due to something dire, like colorectal cancer. While you might find blood in your stool, more often, it is hidden or “occult,” and a colorectal screening helps find it.

Other causes, which are not in any particular order of severity, include:

  • Constipation – which can lead to hemorrhoids
  • Hard stools
  • Angiodysplasia – abnormalities of the blood vessels near the intestine
  • Colon polyps or cancer
  • Ischemic colitis 
  • Proctitis 
  • Pseudomembranous colitis
  • Radiation therapy
  • Rectal cancer
  • Solitary rectal ulcer syndrome
  • Anal fissure – a split or tear in the skin around the anus
  • Anal abscess or fistula – infection around the anus
  • Diverticulitis 
  • Inflammatory bowel disease
  • Damage to the GI (gastrointestinal tract)
  • Bleeding conditions like Vitamin K deficiency, hemophilia, or low platelet count

That’s quite a list, isn’t it? By far, hemorrhoids are the most common cause of rectal bleeding, but the blood could come from anywhere along your digestive tract to be passed with your stool. 

Should you visit an emergency room or urgent care facility? What is the difference? Read more here.


Obviously, the main symptom that probably brings you to a healthcare facility is blood on the toilet paper or stool. Otherwise, the symptoms depend on the severity of the bleeding and where the blood comes from.

Bright red blood is from the lower colon or rectum. It hasn’t passed through any digestive acids or been processed by the body. Usually, red blood coats or mixes with the stool but is visible as a separate component.

Dark, black, tarry stools indicate bleeding higher in the GI tract, and the blood tends to become so mixed with the stool that everything is one color. You might be bleeding anywhere from your esophagus (the tube that takes food to your stomach) to your small intestines and upper colon.

You might:

  • Feel pain or pressure in your rectum
  • See bright red blood on your stool, underwear, toilet paper, or in toilet water
  • Have a stool that’s red, maroon, or black
  • Have stool with a tar-like appearance
  • Experience mental confusion
  • Feel light-headed or dizzy
  • Faint 

The most serious symptom is shock from severe bleeding. Your blood pressure drops suddenly, your heart races, and you might not be able to urinate. You may even become unconscious.

Diagnosing Rectal Bleeding

Besides colorectal cancer screening, physicians have other ways to diagnose the bleeding, including the all-important site of the bleeding. They need to lock down where the blood comes from.

They start with a complete history, including questions such as: 

  • When did the bleeding start?
  • What did you eat the day before seeing it?
  • How frequent are your bowel movements?
  • Have you been constipated?
  • Were you straining on the toilet?
  • Is there blood in the stool, toilet, or when you wiped? What did it look like?
  • Do you have hemorrhoids or an inflammatory bowel condition?
  • Is there a family history of colorectal cancer?

Next, the doctor might perform tests including a physical exam, a blood count to check for anemia, and a fecal occult (hidden) blood test.

If something more is needed, you may receive an endoscopy, which is a direct way to see the bleeding area and detect any lesions or polyps. In some cases, the bleeding is treated during the procedure. 

An endoscopy can show the esophagus, stomach, duodenum, colon, or rectum. The tube goes in the closer end (your mouth or your bum). Don’t worry; you’ll be asleep.

Other testing includes barium X-rays, CT scans, or a technique called gastric lavage if the doctor suspects the bleeding is from the stomach.


Treat the underlying condition, and you treat the rectal bleeding.

Sometimes you just need to change your diet. A lack of fiber often causes constipation, so eating fresh fruits and vegetables and whole grains plus drinking plenty of water can soften the stool and relieve hemorrhoids. An anal fissure can often heal on its own if you soften your stools and treat the area delicately. 

Other conditions may require surgery, typically via endoscopy and using chemical injection, cauterization, or laser therapy. Once the bleeding stops, medication can help prevent future occurrences, especially if the cause is:

  • H. pylori infection
  • Esophagitis
  • Ulcers (often caused by H. pylori)
  • Infections 
  • Irritable bowel disease

Polyp removal and hemorrhoid removal may also be required.

When to Seek Medical Help

It’s always a good idea to speak with a physician anytime you have rectal bleeding. If the bleeding is heavy or you see blood in multiple bowel movements, make an appointment with your doctor immediately. 

Severe rectal bleeding is an emergency, and you need to go to the ER if you have any of the following:

  • Confusion 
  • Cold clammy skin
  • Continuous rectal bleeding
  • Fainting and dizziness
  • Rapid breathing
  • Painful abdominal cramping
  • Severe nausea
  • Blood in your vomit
  • Severe anal pain

Severe bleeding is an emergency. You should seek immediate medical attention, but get someone to drive you if you are experiencing the above symptoms. Come to Family First ER, where we have experienced medical staff who provide high-quality care for people with rectal bleeding. No matter the reason, we provide sensitive, thoughtful care.