Bright Red Blood in Stool: 6 Top Causes & How to Treat

Bright red blood in the stool can occur due to hemorrhoids, anal fissures or diverticuli. It can also be associated with more serious conditions, like intestinal cancer or inflammatory bowel syndrome (which encompasses Crohn’s disease and ulcerative colitis). 

Depending on the cause of the bright red blood, patients may experience additional symptoms, like pain with bowl movements, abdominal discomfort, diarrhea and weight loss. Therefore, identifying the underlying cause is essential for guiding the most appropriate treatment. 

If you notice bright red blood in your stool, you should see your family doctor or a gastroenterologist for assessment. Treatment depends on the underlying cause any may involve simple measures, like increasing fluid and fiber intake, or more invasive approaches, like surgery. 

What causes bright red blood in the stool?

The main causes of bright red blood in the stool include: 

1. Hemorrhoids

Hemorrhoids are more common in those that frequently experience constipation. They are characterized by a dilatation of the veins that surround the rectum due to excessive straining and can occur internally or externally. In addition to bright red blood in the stool, patients may also have other symptoms like discomfort, itching and the sensation of a swelling in the anus. 

Read more about what causes hemorrhoids and the other symptoms associated with them. 

How to treat: Simple measures like increasing water and fiber intake are important to prevent bleeding from hemorrhoids. You can also perform sitz baths in warm water for 15 minutes every day to relieve discomfort. See a list of sitz baths for hemorrhoids that you can prepare at home to help manage pain.

The doctor can prescribe ointments and other medications to help treat hemorrhoids quickly, although some cases may require surgery. Therefore, you should see a gastroenterologist to evaluate the best treatment approach for you. Check out the ways to get rid of hemorrhoids using medication and home remedies. 

2. Anal fissure

Anal fissures can also develop in those that frequently experience constipation. They are characterized by small wounds that surround the anus, and can bleed during bowel movements. The may also cause itching and discomfort when wiping. 

How to treat: To relieve discomfort, you can perform sitz baths in warm water, drink plenty of water, and increase your vegetable intake to ensure your stool is softer and does not cause further injury. You are still advised to see a gastroenterologist for assessment, as the doctor may prescribe ointments to speed-up healing and reduce pain. More serious, deep anal fissures may require surgical repair.

3. Medical exams

Some medical exams, like colonoscopies or prostate checks, can result in the elimination of blood through the stools for several days. 

This occurs because small micro-traumas can occur along the intestinal walls, leading to scan amounts of blood. If polyps are removed or other biopsies are done during a colonoscopy, there may be a higher chance for bleeding post-procedure. 

How to treat: Generally, some bleeding is expected and is not a cause for concern. It typically resolves within 48 hours. Very intense bleeding or bleeding that lasts for longer than 2 days should be assessed by the doctor who performed the procedure or assessed in an emergency room.

4. Diverticulitis

Diverticulitis occurs due to inflammation of the diverticula, which are small finger-like projections along the intestinal walls. In addition to bright red blood in the stool, diverticulitis can cause symptoms like abdominal pain, nausea, vomiting and even fever. 

How to treat: Treatment should be directed by a gastroenterologist and typically involves antibiotics and anti-inflammatories to relieve diverticulitis flare-ups. The diverticula can repeatedly become inflamed, and patients with chronic flare-ups should adhere to a diverticulitis diet

5. Crohn’s disease

Crohn’s disease is a chronic condition that is associated with intense intestinal inflammation. This disease can cause symptoms like blood stools, constant diarrhea, loss of appetite, strong abdominal cramping and weight loss. 

How to treat: If you suspect you may have Crohn’s disease, you should be assessed by your family doctor or gastroenterologist. If confirmed, treatment usually involves the use of medications that reduce immune system responses to prevent new flare-ups. Learn more about the IBS diet that your doctor may recommend to help manage symptoms and flare-ups. 

6. Intestinal cancer

Although this is rare, bright red blood in the stool may be a sign of intestinal cancer. Generally, patients with intestinal cancer will experience other symptoms, like changes to bowel movement patterns, fatigue and weight loss. 

How to treat: If you suspect you may have intestinal cancer, you should consult your family doctor or gastroenterologist. The doctor will order testing, like a colonoscopy or CT scan, to confirm or rule out a diagnosis.