Blood in your stool may be due to a number of factors, such as straining to poop, anal fissures, and hemorrhoids. Treatment depends on the specific cause of your constipation and bleeding.

Many people experience constipation from time to time. If you’re constipated, you may have:

  • fewer than three bowel movements per week
  • dry, hard, or lumpy stools
  • pain or difficulty passing stools
  • a feeling that not all stool has passed after a bowel movement

Constipation can be caused by many factors, including diet, certain health conditions, and some medications. Even simple changes in your daily routine can cause bowel movements to become irregular.

For some people, constipation can become chronic. This means they experience symptoms of constipation for 3 or more months. If the exact cause of chronic constipation isn’t known, it’s called chronic idiopathic constipation.

No matter the cause, straining to poop when constipated can lead to rectal bleeding. In some cases, underlying health problems can lead to both constipation and bleeding. These symptoms can sometimes be a signal that something serious is going on, and more investigation may be needed.

In this article, we examine some of the common causes of bleeding with constipation, how they can be managed, and when it’s time to see a doctor.

Bloody stools can happen for a variety of reasons, especially alongside constipation. In many cases, both constipation and bleeding can be managed with at-home care, but some causes may be more serious and require further treatment.

Some of the possible causes of bloody bowel movements with constipation include:

Hemorrhoids

Hemorrhoids are swollen, inflamed blood vessels found around the anus or in the lower rectum. They may be external or internal, though bleeding is more common with internal hemorrhoids.

Hemorrhoids are very common — about half of adults over age 50 have them and they are also common during pregnancy. They can happen as a result of straining or from sitting on the toilet for long periods, both of which are common with constipation. They are also the most common cause of rectal bleeding.

Anal fissures

An anal fissure is a tear in the lining of the anus that can cause bleeding. Constipation is a common cause of anal fissures, and they typically happen because of tissue damage when passing hard stools. They most often affect children and middle-aged adults and are also common during pregnancy.

Anal fissures can sometimes be mistaken for hemorrhoids, so an examination by a doctor is needed to differentiate between the two. Pain that lingers for several hours after a bowel movement is one possible indicator of anal fissures.

Fecal impaction

Fecal impaction occurs when a lump of dry, hard stool becomes stuck in the colon or rectum. It commonly occurs in people with chronic constipation.

Rectal bleeding is a common symptom of fecal impaction. You may also experience abdominal cramps, bloating, and straining when passing stools.

Rectal prolapse

A rectal prolapse happens when part of the lower intestine — the rectum — drops down through the anus. It’s not very common, but most people who do experience rectal prolapse are women and typically over 50 years of age. One of the most common causes of rectal prolapse is weak pelvic floor muscles.

Constipation can happen with rectal prolapse. If the prolapse leads to ulcers in the rectum, it can also cause bleeding. Heavy rectal bleeding may be a sign of serious complications from rectal prolapse and requires urgent medical attention.

Diverticular disease

Diverticula are small pouches that form in the wall of the colon. They don’t usually cause symptoms, but they can sometimes lead to inflammation and other problems, such as constipation.

If one of the blood vessels in these pouches bursts, it can also cause bleeding. Bleeding may come on very quickly and can be very serious. Other symptoms that may suggest serious complications from diverticular disease include:

  • severe pain in the lower left of the abdomen, typically with sudden onset
  • fever or chills
  • nausea or vomiting

Proctitis

Proctitis refers to inflammation in the rectum. Several conditions can cause proctitis, including inflammatory bowel disease (IBD), infections, and certain medications.

Chronic inflammation in the rectum can damage the intestinal lining and lead to bleeding. It can also cause difficulties with bowel movements.

Colorectal cancer

Cancer may be the first thing many people worry about when they see blood in their stool, but it’s a relatively uncommon cause of rectal bleeding. Because cancer can be associated with ongoing bouts of rectal bleeding, however, it may be misdiagnosed as hemorrhoids.

Colorectal cancer may cause blood in the stool, as well as symptoms such as:

  • a change in bowel habits lasting more than a few days
  • rectal bleeding with bright red blood
  • a feeling that your bowel doesn’t empty all the way after a bowel movement
  • abdominal pain or cramping
  • unintentional weight loss

The Centers for Disease Control and Prevention (CDC) recommends that people are routinely screened for colon cancer beginning at the age 45. Colorectal cancer can be effectively treated and even cured if caught early, so it’s important to see your doctor or a gastroenterologist as soon as you notice symptoms.

Signs of an emergency

If you’re experiencing heavy bleeding or have severe abdominal pain or cramping, you may need urgent medical care. Other symptoms of a medical emergency include:

  • fast or heavy breathing
  • a rapid heart rate
  • weakness or fatigue
  • dizziness

If you’re experiencing any of these symptoms with rectal bleeding, go to an emergency room or call your doctor right away.

Pay attention to what the blood looks like

The color and texture of the blood in your stool can provide clues as to what might be the underlying cause. Bright red blood suggests a source in the colon or rectum, such as hemorrhoids or diverticular disease. Darker blood with black, tarry stool suggests a bleed higher up in the digestive tract.

Blood that can be seen when wiping but not in the stool may indicate an external cause, such as hemorrhoids or anal fissures.

While the appearance of the blood may offer some insight as to the source of the bleeding, an examination by a doctor is still needed to rule out other, more serious causes.

Other symptoms that happen alongside constipation and rectal bleeding may help your healthcare team better identify the cause. Be sure to alert your care team if you’re experiencing any of the following symptoms:

  • abdominal pain, cramping, bloating, or pressure
  • painful bowel movements
  • weight loss
  • diarrhea
  • mucus in stool
  • fecal incontinence
  • itching, tenderness, or pain around the anus
  • recurring or long lasting symptoms

A healthcare professional — typically a gastroenterologist — will perform an exam to determine the cause of rectal bleeding.

A digital rectal exam can help them feel lumps or tears that happen internally. During this exam, a doctor inserts a gloved, lubricated finger into the rectum.

Your doctor may also perform a colonoscopy to help with imaging further up in the intestines. During a colonoscopy, the doctor uses a long, flexible tube with a small camera attached to examine the inside of the colon. You’ll likely be sedated during a colonoscopy.

Other types of tests you may have include:

  • X-rays or computed tomography (CT)
  • magnetic resonance imaging (MRI)
  • ultrasound
  • nerve or muscle tests
  • blood or stool tests

Constipation can usually be relieved by eating a high fiber diet, drinking plenty of liquids, and taking a laxative or stool softener. These can also help relieve bleeding caused by constipation or constipation-related conditions such as hemorrhoids or anal fissures.

Depending on the cause of constipation and bleeding, additional treatments may be needed. These may include prescription medications as well as surgery.

What is the difference between blood in stool and blood when wiping?

Blood may be visible in the stool itself, or it may only show up on toilet paper when wiping. Blood that is only visible when wiping is more likely to indicate a hemorrhoid or anal fissure, but an examination is needed to confirm.

How much blood in stool is OK?

No amount of blood in stool is “normal,” and you should discuss any new bleeding with a doctor.

If bleeding continues after you and your doctor have developed a treatment plan, more testing or treatment may be needed to get to the root of the problem.

Is bright red blood in stool serious?

Bright red blood in the stool typically indicates a source of bleeding in the lower intestines, like the colon or rectum. The color itself doesn’t indicate how serious the cause is, but it may help your doctor narrow down possible causes.

If the bleeding is heavy or continuous or is accompanied by severe abdominal pain or cramping, you should seek emergency medical care.

When should I worry about blood in stool?

Any amount of blood in stool should be discussed with a doctor. Some additional signs that bleeding may be caused by something serious include:

  • chest pain or shortness of breath
  • pain in the abdomen, pelvis, or rectum
  • fever
  • dizziness, nausea, or vomiting
  • unexplained weight loss
  • abnormal bloodwork

Bleeding is not uncommon with constipation and can be caused by a variety of factors. While most cases can be managed at home with self-care, constipation and bleeding can sometimes be a sign of a more serious problem.

If you experience any amount of bleeding — even if it comes and goes — you should speak with a doctor to help pinpoint the cause and determine what treatment may be needed.