Rectal Bleeding (Blood in Stool)

What is rectal bleeding?

Noticing blood in your stool may be alarming. The alarm that something is amiss can trigger fears and raise many questions. Generally, rectal bleeding is a sign of different problems, which can range from minor to severe. It’s important to identify the underlying cause of the condition.

While certain causes, such as haemorrhoids, might not require treatment, conditions including colorectal cancer necessitate immediate medical attention. Other potential causes include ulcers, inflammatory bowel disease (IBD), and anal fissures. Your doctor will help identify the reasons for your hematochezia, which is the medical term for blood in stool or rectal bleeding.

How does rectal bleeding appear?

Rectal bleeding can appear in different ways, such as:

• Seeing fresh blood on toilet paper after wiping.
• Noticeable blood in the toilet bowl after a bowel movement, sometimes making the water appear red.
• Stool that appears dark red, bright red, or tarry black.

Rectal bleeding refers to blood coming from the anus, although the bleeding might originate from any part of the gastrointestinal (GI) tract. The stomach, colon, small intestine, rectum, and anus form a continuous passage, and all gastrointestinal bleeding exits through the same route.

What does blood in stool look like?

Blood in stool can appear in various ways. You might notice bright red blood streaks on your stool, blood clots, or a mixture of blood and mucus. In some cases, your stool can be black, darker, or tarry. The colour of the blood gives clues about where the bleeding is originating from:

• Bright red blood often indicates bleeding in the lower part of the colon, rectum, or anus.
• Dark red or maroon blood may signify bleeding higher up in the small intestine or colon.
• Black stool (melena) usually indicates bleeding in the stomach, such as from a stomach ulcer.

Occasionally, rectal bleeding may not be noticeable to the naked eye. This condition is called occult bleeding and may only be detectable under a microscope. A lab test known as the fecal occult blood test (a screening method for colorectal cancer) performed on a stool sample can detect this form of blood.

Is rectal bleeding serious?

Although rectal bleeding can be serious, it’s not always the case. Therefore, it’s advisable to talk with your doctor if you notice blood in your stool. Minor problems don’t always require treatment. However, intervention is sometimes necessary, as it may indicate a more severe condition.

Is bright red blood in my stool more serious than darker blood?

Bright red blood can be alarming as it usually points to active bleeding. Darker blood often indicates older bleeding that is no longer active. However, darker stains in the stool could be misleading and don’t necessarily imply that the bleeding has ceased. Instead, it could be originating from a higher part of the tract.

It takes longer for bleeding from the upper GI tract to leave the body and exit through the anus. Digestive chemicals gradually darken the blood inside as it travels. In contrast, bright red blood in the stool originates from the lower region and might be due to something less serious, like a wound. However, upper gastrointestinal bleeding is unlikely to be harmless.

When should you be concerned about rectal bleeding?

Consulting a healthcare provider whenever you see blood in your stool is a good idea, particularly if:

• You’re uncertain of the cause: Sometimes, blood in the stool is linked with a known health condition you have. You may not be surprised when you notice bleeding, especially if you have diarrhoea, constipation, or a chronic bowel disease. However, it is more concerning and unexpected if blood in the stool is the first indication of a gastrointestinal disorder.
• It causes pain: Pain is usually a warning sign that something may be wrong in your body. It’s important to pay attention to where the pain occurs. Pain from the anus or rectum may indicate a fresh wound, while lower abdominal pain could signal colitis (inflammation of the colon lining) with various causes. Conversely, black stools and upper abdominal pain could indicate a stomach-related problem.
• It is heavy or recurrent: Consistent or heavy bleeding can result in severe blood loss, leading to anaemia or hypovolemic shock in rare cases. If you experience sudden, serious bleeding, or if it persists for several days, seek medical care immediately. You should also visit the emergency room if your blood pressure drops suddenly and you start feeling dizzy or faint.
• It has persisted for a week or more: Even minor bleeding without pain requires attention if it persists. Over time, a slow bleed could eventually result in significant blood loss, and it could indicate a condition that is not improving and may be causing further damage apart from blood in the stool.

Causes

Rectal bleeding, or hematochezia, can occur for various reasons, ranging from mild and common to more serious and rare problems requiring immediate medical care. Some symptoms can sometimes provide clues about the underlying cause.

Common causes of rectal bleeding include:

• Haemorrhoids: Also known as piles, haemorrhoids are inflamed veins in the rectum or anus. They are common and the major cause of blood in stool. The veins can swell near the skin surface, sometimes breaking the skin and causing bleeding. Piles are usually not serious and are associated with pressure or strain from heavy lifting, bowel movements, or pregnancy.
• Anal fissure: This is a tear in the anal canal lining. Anal fissures can be easily confused with haemorrhoids and usually occur due to straining to pass hard stools. Both are associated with constipation and may lead to pain and bleeding, but a fissure tends to cause more pain. While both can heal independently, treatment is sometimes required.
• Inflammatory bowel disease (IBD): This causes ongoing inflammation in the lining of the small and large intestines. Crohn’s disease mainly affects the small intestine, whereas ulcerative colitis primarily affects the large intestine. IBD results in diarrhoea and chronic abdominal pain, and it can also cause bleeding in severe cases.
• Diverticulitis: This occurs in the lower end of the colon, near the rectum. It is caused by infection and inflammation of diverticula, which are small pockets in the colon's inner lining. The inflammation can weaken blood vessels in the area, making them more prone to rupture, leading to acute rectal bleeding.

Additional possible causes of rectal bleeding include:

• Infectious colitis: Certain bacterial infections, such as E. coli and C. difficile, can lead to haemorrhagic colitis, which is bleeding from the colon. It often manifests as bloody diarrhoea. If you have an infection, you will likely notice it, and in most cases, it will resolve on its own; however, some may require antibiotics. It’s advisable to contact your doctor if you feel unwell for more than a few days.
• Sexually transmitted infections (STIs): Common STIs such as chlamydia, gonorrhoea, and syphilis can cause inflammation and bleeding in the anal or rectal lining. Herpes may also trigger sores that could bleed, while human papillomavirus (HPV) can lead to anal warts that might slightly bleed. Most STIs require specific treatment to resolve; hence, proper diagnosis is essential.
• Peptic ulcer disease: Peptic ulcers occur in the stomach or the duodenum, the upper part of the small intestine. They develop when stomach acid erodes the protective lining, causing open sores. These ulcers can lead to burning or gnawing stomach pain and might also bleed. Since bleeding from the upper gastrointestinal tract usually takes longer to pass through, blood may appear black, dark, or tarry.
• Colon polyps and colorectal cancer: Colon polyps can resemble mushrooms developing out of the bowel lining. They are common, and larger polyps may sometimes bleed or become cancerous. Cancerous polyps are at a higher risk of bleeding compared to non-cancerous ones. To rule out cancer, the doctor will recommend a colonoscopy to assess unexplained causes of blood in stool.

Can too much straining during bowel movements cause rectal bleeding?

Yes. Straining during bowel movements and constipation can lead to rectal bleeding. Straining can cause problems such as anal fissures or haemorrhoids, which are likely to bleed. Extremely hard stools can also tear the inner skin of the anus, leading to bleeding. Addressing constipation can thus help prevent these issues.

Are the causes of rectal bleeding similar for babies or children?

Yes, babies and children can also develop haemorrhoids and anal fissures due to straining during bowel movements. Anal fissures are a common cause of rectal bleeding among children. Minors are also prone to infectious colitis; however, they are unlikely to develop chronic conditions such as inflammatory bowel disease, colon cancer, or diverticulitis, which typically take time to advance.

Are the causes of rectal bleeding similar for men (AMAB) or women (AFAB)?

Many causes of rectal bleeding are similar regardless of gender. However, women and those assigned female at birth (AFAB) may also develop endometriosis, which in rare cases can lead to rectal bleeding if it affects the lower bowel or rectum. During the menstrual cycle, the tissue may bleed or become inflamed.

Can foods contribute to the appearance of blood in stool?

Some foods can alter the colour of your stool. If you notice bloodstains after a bowel movement, consider your recent meals. Foods like beets, blackberries, tomatoes, or red food colouring can make stool appear bloody or red. Additionally, taking iron supplements can result in dark or black stools.

Diagnosis

How do doctors determine the cause of rectal bleeding?

Healthcare providers can assess rectal bleeding using various methods to determine its underlying cause. They usually begin by inquiring about the events surrounding the condition to narrow down the potential reasons for blood in your stool.

Your provider might also ask the following:

• When did you start seeing blood in your stool?
• Is there pain associated with the bleeding?
• Do you notice any blood in your stool or when wiping?
• How does the blood in the stool look? Are there clots or streaks?
• What was the appearance of your stool? Was it runny or hard?
• Do you have constipation or diarrhoea?
• Did you strain to pass stool when you noticed blood?
• How often do you have bowel movements?
• What did you eat before you saw blood in your stool?
• What medications did you take the day before you noticed bleeding?
• Did you consume alcohol before the bleeding occurred?
• Do you have diverticulosis?
• Do you have haemorrhoids?
• Do you have inflammatory bowel disease (IBD)?
• Does any member of your family have or have had colorectal cancer?

Based on your responses, the doctor will determine which medical tests to conduct next. These might include:

• Digital rectal exam: A physical examination of the rectum and anus.
• Anoscopy: Using a small scope with a magnifier to examine the anal canal.
• Proctoscopy: Examining the rectum and anus with a short, rigid scope.
• Flexible sigmoidoscopy: Checking the lower colon with a longer scope.
• Rectal culture swab: Identifying infections through bacterial culture.
• Stool test: Analysing stool samples for signs of occult blood, active bleeding, inflammation, or specific infections.
• Colonoscopy: Examining the entire large intestine with a colonoscope (an illuminated camera at the tip of a long tube). This is a common screening procedure for colon cancer.
• Upper endoscopy: This may be recommended if upper gastrointestinal bleeding is suspected. It involves passing an endoscope down the throat into the stomach and duodenum.

Care and Treatment

What is the treatment for rectal bleeding?

Typically, treatment for rectal bleeding involves addressing the underlying condition that is causing the bleeding. The specific treatment option will depend on the cause, which may vary. If reachable haemorrhoids or an anal fissure is the reason for blood in stool, topical ointments can often be used to treat them at home.

Will rectal bleeding resolve on its own?

Depending on the cause, rectal bleeding may resolve on its own. If the bleeding stops and does not return, additional treatment may not be necessary. However, it is important to monitor for any blood in the stool and note if it occurs more than once or if other symptoms accompany it.

When to Call the Doctor

When should I consult a healthcare provider about rectal bleeding?

It’s advisable to contact your doctor when you notice blood in your stool, as it could be a sign of a more serious condition that requires treatment. Seek immediate care if you see large blood clots when passing stool or if you experience heavy bleeding. Black and tarry stool may indicate an upper gastrointestinal bleed.

Questions to ask your healthcare provider

You will want to understand why you have rectal bleeding and how to address it. Therefore, your doctor will seek to determine the cause and the type of treatment you might require. During this time, consider asking the following questions:

• Is my rectal bleeding linked to a condition I already know I have?
• What other signs and symptoms should I be aware of?
• What examinations do I need to determine the cause of my condition?
• What are the treatment options for my condition?
• How should I care for myself while experiencing rectal bleeding?
• Can I avoid future occurrences by adjusting my medications, diet, or lifestyle habits?

A Note from MD.co.uk

Bleeding can trigger deep, intuitive anxiety, especially when the source is unknown. Waiting for a doctor’s appointment to determine the cause of your rectal bleeding can be difficult. However, remember that although there are numerous possible reasons, the common ones are often straightforward to identify and address.

Discussing your rectal bleeding with your doctor should not be something to be ashamed of. These symptoms are important, and your provider will want to understand every detail. Being open and honest when answering their questions will also assist them in determining the right treatment for you.