Diverticulitis can cause rectal bleeding. In fact, diverticular bleeding is the most frequent cause of lower gastrointestinal bleeding.

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Diverticulitis is a condition where small sacs that have bulged in your intestine (diverticula) become inflamed.

People who have diverticulitis often have no symptoms, but sometimes complications are possible. One common complication is rectal bleeding. The bleeding can range from mild to severe.

Let’s take a look at what diverticular bleeding looks like, how long it typically lasts, how it’s treated, and what the outlook is for people who experience it.

Diverticulitis is more likely to affect people as they get older. About half of all people over the age of 60 have it. While most people with diverticulitis don’t have symptoms, others experience symptoms such as:

  • bloating
  • stomach cramps
  • one-sided abdominal pain
  • bleeding

Diverticular bleeding leads to almost 200,000 hospital admissions in the United States per year and is the most frequent cause of lower gastrointestinal bleeding. Fewer than 5% of people with diverticulosis will experience diverticular bleeding.

When diverticular sacs bleed, the bleeding can range from mild to severe. Some people notice a little fresh blood mixed in with their stool when they use the toilet. But other people might notice large blood clots that get passed during particularly challenging diverticulitis episodes.

The majority of diverticular bleeding cases are mild and resolve on their own without treatment. However, about 10% to 20% of people will experience diverticular hemorrhaging, where large amounts of blood are lost.

Diverticular hemorrhaging may become serious, resulting in severe symptoms such as blood loss and dehydration. In very rare cases, fatalities can result.

Anytime you are experiencing rectal bleeding — whether you’ve been diagnosed with diverticulitis or not — you should see a healthcare professional promptly.

In order to diagnose diverticular bleeding, your healthcare professional will take your medical history and do a physical exam to try to identify the source of your bleeding. You may be asked questions about what your bleeding has been like, how long it’s gone on, and whether any pain is involved. You may also be asked questions about changes in bowel movements and how your overall health has been.

Your physician will likely:

  • take your vital signs and blood pressure
  • listen to your heart
  • palpate your abdomen
  • perform a rectal exam
  • order lab tests that might include blood work to measure complete blood count, liver function, and kidney function
  • perform or order imaging tests that may include CAT scan or barium X-rays
  • perform or order an endoscopy, such as a colonoscopy or sigmoidoscopy

If you’re hospitalized for rectal bleeding, you are likely to have a diagnostic colonoscopy, especially if you haven’t had a good quality colonoscopy recently.

The treatment for diverticular bleeding depends on how severe the bleeding is and what other complications or comorbidities are present.


Researchers estimate that in 70%–80% of people with diverticular bleeding, it will go away on its own, but about 38% of people will experience a recurrence of bleeding. In cases where the bleeding doesn’t resolve on its own or is severe, supportive care and treatment in a hospital may be necessary.


If your bleeding is severe enough to require hospitalization, usually rest and supportive care in the hospital are all that’s required. Sometimes, minimally invasive techniques work to stop the bleeding.


In addition to helping diagnose diverticulitis, sometimes active bleeding may be identified and treated during endoscopic procedures like a colonoscopy without the need for surgery.

If you have diverticulitis, you’re also recommended to have a follow-up colonoscopy 6 to 8 weeks after recovery if you haven’t had a recent good quality colonoscopy before the attack.


During angiography, a wire is moved through the blood vessels in an effort to pinpoint the source of your bleeding. Substances that stop bleeding may also be injected during this procedure.


If your bleeding isn’t resolving and is severe, surgery may be an option, including surgery to remove part of your colon.

Some people are more likely to experience diverticular bleeding than others, including:

The vast majority of people, up to 80%, will experience a spontaneous resolution of their bleeding. Some people will experience rebleeding at some point in the future. Between 22% and 38% of people will have episodes of rebleeding. Individuals 80 years old or older are more likely to experience rebleeding.

If bleeding can’t be managed at home or is severe, you might need hospital care, which could involve IV fluids or blood transfusions. Sometimes minimally invasive techniques such as angiography will be used. At other times, surgery will be necessary.

For most people with severe rectal bleeding, it can be resolved with these interventions. Deaths are rare but possible.

If you have rectal bleeding, it’s vital that you get a formal diagnosis to rule out any other potential causes. Besides diverticulitis, other causes of lower gastrointestinal bleeding can include:

What is the main cause of diverticulitis?

Most physicians believe that the main cause of diverticulitis is eating a low fiber diet, which can cause constipation. Pressure from stool that doesn’t pass, as well as straining during bowel movements, can trigger the condition.

What color is the blood from diverticular bleeding?

In most cases, blood from diverticular bleeding is red or maroon. Dark clots are possible, and the blood may be mixed with stool.

What kind of doctor should I see for diverticular bleeding?

You can visit your primary care doctor if you have rectal bleeding, but it’s likely that they will refer you to a specialist. In most cases, you will be referred to a gastroenterologist, a physician who specializes in gastrointestinal conditions.

Experiencing rectal bleeding can be distressing. If you have diverticulitis, you might wonder whether the bleeding you’re experiencing is from that. If you’ve never been diagnosed with diverticulitis, you might also be wondering whether that’s the cause of your bleeding.

Either way, anytime you are experiencing new rectal bleeding, it’s important to visit your doctor so that the cause can be correctly identified and you can receive the treatment you need.