Blood in the stool can take on many forms. You may notice streaks of blood in the stool or the toilet bowl. You may also see changes in stool color. Sometimes, the only sign of bleeding may be a few red specks on your toilet paper.

Experiencing rectal bleeding can be alarming. Especially when you don’t know what’s causing it. But seeing a doctor can help you address this problem and reclaim control over your health.

This article will first highlight when you should see a doctor for rectal bleeding. We’ll also discuss the potential causes of blood in stool and the signs you should look out for. Lastly, we’ll outline how to diagnose rectal bleeding.

When to See a Doctor

Rectal bleeding is never normal. If you notice blood in your stool, you should see a doctor to make sure it’s not a sign of a severe medical condition. Blood in the stool can have many causes ranging from mild to severe. But you’ll only know the actual cause after your doctor evaluates you.

Finding the root cause of rectal bleeding promptly can make treatment more successful. Many medical conditions have better treatment outcomes when caught early.

You should also see a doctor if rectal bleeding occurs with other symptoms such as:

  • Abdominal pain
  • Bloating
  • Constipation
  • Diarrhea
  • Difficulty swallowing
  • Thin, pencil-like stools
  • Unexplained weight loss

Causes of Blood in Stool

Many medical conditions can result in rectal bleeding. Common causes of blood in stool include:

  • Hemorrhoids. Swollen or inflamed veins inside the rectum can start to bleed when straining during a bowel movement. Passing hard stools can also damage hemorrhoids and lead to blood in the stool.
  • Anal fissures. Tears in the lining of the anal canal often cause bleeding during bowel movements due to increased pressure within the anal canal.
  • Proctitis. Inflammation of the rectum lining can cause tiny tears to form, which can result in rectal bleeding.
  • Polyps. Colon polyps can bleed when growing to form colon cancer. Sometimes, this is the only sign that something is wrong.
  • Colon cancer. Tumors like colon cancer produce a network of blood vessels that enable them to grow. These blood vessels tend to be leaky, which can cause rectal bleeding.
  • Diverticulitis. When small pouches in the colon become inflamed and infected, the infection can eat through the colon’s lining. This can cause painful bleeding.
  • Crohn’s disease. This chronic inflammatory condition can affect the entire digestive tract. Chronic inflammation can wear down the digestive tract lining and lead to the formation of ulcers. The ulcers can expand in size and cause slow or heavy bleeding.
  • Ulcerative colitis. This inflammatory condition is similar to Crohn’s disease but only affects the colon. With ulcerative colitis, the body’s immune system attacks the lining of the colon, which can cause ulcers and bleeding.

Colon Cancer Symptoms

For many people, colon cancer goes undetected because it often lacks symptoms. But, sometimes, there are underlying signs that can make the difference between life and death.

Blood in the stool is one symptom of colon cancer. While mild conditions often cause bleeding, it’s important to see a doctor to rule out other causes like colon cancer. I’ve seen many people who ignored rectal bleeding for years because they assumed it was from hemorrhoids. Sadly, this resulted in late-stage colon cancer diagnosis in too many cases.

Other colon cancer symptoms include:

  • Change in bowel habits
  • Change in consistency of stool
  • Unexplained weight loss
  • Abdominal pain
  • New-onset weakness or fatigue

If you experience any of the above symptoms, you should contact your doctor.

And, most importantly, don’t forget to get screened for colon cancer. Getting screened can detect colon cancer early and save your life.

Changes in Stool Color

Changes in stool color can signify where bleeding in the digestive tract occurs. Depending on the location of the bleeding, blood in the stool may appear lighter or darker.

Bright Red Blood in Stool

Bright red blood in stool usually means bleeding occurs in the lower part of the digestive tract, such as in the colon or rectum. This type of blood appears fresh because it doesn’t undergo digestion.

The following medical conditions may cause bright red blood in stool:

  • Anal fissures
  • Hemorrhoids
  • Diverticulitis
  • Proctitis
  • Rectal ulcers
  • Colon cancer

Consuming red-colored foods such as beets and red licorice can also give stool a red tint.

Black or Dark Red Blood in Stool

The longer blood is in the digestive tract, the darker it appears. Black, tarry stools are a sign of bleeding in the upper part of the digestive tract, such as the esophagus, stomach, and first part of the small intestine. Dark red blood in stool is a sign that bleeding may be in the small intestine or the beginning of the colon.

Causes of black or dark red blood in the stool may include:

  • Inflammatory bowel disease
    • Crohn’s disease
    • Ulcerative colitis
  • Colon cancer
  • Peptic ulcer disease
  • Gastritis
  • Esophagitis
  • Variceal bleeding
  • Mallory-Weiss syndrome

Of course, not all changes in stool color are due to underlying disease. Certain foods and supplements can also change the color of stool. For example, iron supplements and Pepto-Bismol are known to cause black stools. Black or dark red blood in the stool may also result from eating dark-colored foods like blueberries, black licorice, and dark chocolate.

Diagnosis of Blood in Stool

The diagnosis of blood in the stool depends on the severity of your symptoms.

Emergency Situations

In some cases, rectal bleeding needs emergency treatment. You should go to the ER immediately if you experience any of the following symptoms:

  • Gushing blood from the rectum
  • Fever
  • Severe abdominal pain
  • Fainting
  • Dizziness or lightheadedness
  • Cold and clammy skin
  • Accelerated heart rate
  • Blurred vision
  • Reduced urine output
  • Nausea

These symptoms are signs of a large volume of blood loss and can result in death without immediate intervention.

Non-emergency Situations

If your symptoms are mild, you can schedule an appointment with your doctor.

The diagnosis of blood in the stool starts with an evaluation of your medical conditions, risk factors, and medications. Depending on your symptoms, you will then undergo testing to visualize the digestive tract and find the source of bleeding.

Testing in non-emergency situations may include:

  • Rectal examination
  • Anoscopy
  • Colonoscopy
  • X-ray studies
  • Barium enema
  • CT scan

The Bottom Line

Blood in the stool is always abnormal. While seeking help for this symptom can feel uncomfortable, don’t let embarrassment stop you from seeing a doctor.

Discussing bowel movements with your doctor may seem odd. But the more information you can provide, the better we can help remedy the situation.

Rectal bleeding has many causes, some of which are more serious than others. While most are mild, it’s essential to rule out severe medical conditions. Unfortunately, some conditions can be life-threatening if left untreated.

If you’re experiencing blood in the stool or other digestive symptoms, you can make an appointment online or call our office at (210) 615-8308.