Blood On The Outside Of The Stool: 7 Causes & When To Worry.
Blood on the outside of the stool is usually caused by disease of the rectum and anal canal. The most common causes are hemorrhoids, anal fissures, rectal polyps, and anal or rectal cancer.
Why Blood appears on the “outside” of the stool (and not mixed with it)?
You may get scared when you see red blood on the outside of your stool. Fortunately, the majority of cases are benign.
But Before we dive into the cause, I will explain to you why the blood sometimes appears on the “outside” of stool?
Your stool gradually acquires its semi-hard form as it passes through your colon. How blood is mixed with your stool depends on the site of the bleeding source.
- Bleeding sources early in the colon or all intestine: usually result in complete mixing of blood with stool (which may also turn blackish).
- Bleeding from the last part of the colon: Anal canal, Rectal, and sigmoid colon bleeding can lead to blood on the outside of the colon.
In other words, blood joining stools after being formed appears on the outside of the stool. And this usually happens if the bleeding site is in the last part of your colon (particularly the rectum and anal canal)
Why you shouldn’t Panic?
The good news is the majority of causes blood on the outside of your stool are usually benign in nature.
Minimal Bright red blood per rectum occurs in about 15% of the adults (3 of every 20 people) (ref). So, it is a common condition even in younger adults.
In the vast majority of cases, piles (hemorrhoids), or piles. those two causes represent up to 95% of causes.
Other serious causes are very rare and usually have warning signs.
However, You must have a diagnosis from your doctor. don’t ignore any form of bleeding per rectum, especially if you are older than 40 years.
Common causes of blood on the outside of the stool:
(1) Piles (hemorrhoids):
Piles or hemorrhoids present is far the most common cause of blood on the outside of your stool. According to current statistics, it present in up to 95% of people.
Piles are common in people with chronic constipation. Either with constipation-predominant IBS or Chronic Idiopathic Constipation.
Hemorrhoids are dilated and enlarged blood vessels in the wall of your rectum or anal canal.
Constipation is not the only cause of hemorrhoids, an
Sings and symptoms suggesting hemorrhoids:
- Painless bleeding: usually the blood you see on the outside of the stool or the toilet paper is not associated with pain (unless inflamed hemorrhoids).
- With Inflamed Hemorrhoids: bleeding can be painful, associated with some itching around the anus.
- A skin tag may be present at the opening of the anal canal (with external hemorrhoids).
How to manage bleeding from hemorrhoids:
- It is important to get the diagnosis confirmed by your doctor.
- colon cancer is sometimes diagnosed in people who have ignored bleeding for years as they assumed it was from piles.
- avoid constipation using laxatives, stool softeners, and a high fiver diet.
- Ask your doctor about the proper medication and the need for surgery.
(2) Anal Fissure:
Another common cause of blood on the outside of your stool is anal fissures. An anal fissure usually causes pain during defecation.
It is usually caused by trauma to the anal tissue. commonly due to the passage of hard stool (constipation), and during normal vaginal delivery in females.
Symptoms and signs suggesting anal fissure:
- History of chronic constipation, or any trauma to the anal canal.
- Pain: pain usually very severe and agonizing during defecation, and mild or absent in between bowel motions.
- the color is bright red, usually on the outside of the stool.
- In severe cases, it may cause lower back pain.
What to do if your suspect anal fissure:
- Consult your doctor to confirm the diagnosis, and treat the cause.
- Usually, the characteristic history is sufficient for the doctor, but it may ask you for a “digital Rectal Examination” to confirm the diagnosis.
- Prevent hard stool by taking laxatives, stool softeners, and high fiber foods.
- Ask your doctor about the best medications (local gel or cream plus pain pills) if the condition is severe.
(1) sigmoid or rectal polyp
Colon polyps are very common (about 30% of Americans will have it at the age of 50).
A polyp is a finger-like or cone-like growth inside your colon’s inner wall. when a polyp grows in the last part of your colon (sigmoid and rectum) may ulcerate and cause blood outside the stool.
Basically, there are 2 types of polyps:
- Inflammatory polyps (low tendency to turn malignant): it is also called “hyperplastic polyp”, and can be a source of bleeding on the outside of your stool.
- Adenomatous Polyp (Relatively higher risk of turning malignant): especially if it is larger in size.
Symptoms suggesting colon polyps:
- No symptoms: usually most colon polyps persist for years without any symptoms. and occasionally discovered when it causes bleeding. also, many of them are discovered accidentally during colonoscopy.
- Bleeding: This can range from streaks of blood on the outside of stool to frank bleeding per rectum.
- Pain: but it is uncommon.
NOTE: because of the asymptomatic nature and the potential for malignancy, you should start testing for these polyps at the age of 45-50. This is because the incidence of colon polyps increases with age.
(2) Rectal ulcer.
A rectal ulcer is a painful sore inside the rectum. It can be caused by:
- Constipation and straining.
- IBD (chrons or Ulcerative Colitis).
- Solitary Rectal Ulcer Syndrome (unknown cause).
Signs and symptoms suggesting rectal ulcer:
- The ulcer may occasionally bleed (especially with constipation) leading to blood on the outside of the stool.
- Pain in the rectum (which may radiate to the lower back).
- Painful bowel movements (similar to symptoms of anal fissures).
- A sense of incomplete evacuation of your rectum
It is difficult to tell the difference between some rectal/anal ulcers and anal fissures. always check for the cause with your health care provider.
(3) Rectal inflammation (Proctitis).
your rectal lining can get inflamed either alone (Proctitis) or together with sigmoid colon inflammation (Rectosigmoiditis).
The main causes of Proctitis:
- Sexually transmitted diseases (Gonorrhea, Genital Herpes, Chlamydia infection).
- Other infections: Such as Bacillary dysentery, Salmonella, Campylobacter infection).
- Inflammatory Bowel Disease (IBD).
- Some medications (especially antibiotics).
- Rectal Radiotherapy & others, Learn more HERE.
Signs and symptoms suggesting Proctitis:
- Dysentery: usually you experience dysentery or dysentery-like symptoms, where the stool becomes looser.
- And is associated with blood, mucous, or both.
- Lower abdominal pain with or without fever.
- Kown history of IBD, or STD.
(4) Rectal or anal Cancer.
In the USA, Colorectal cancer is the second cause of death in men (and the third in women).
However, it is a relatively rare cause of blood on the outside of stool compared to piles and anal fissures).
Only rectal or anal cancer can cause blood on the outside of stools. classical colon cancer usually results in red or blackish blood MIXED with stools.
How to suspect recall or anal cancers:
- Anal or Rectal Pain: continuous dull Pain.
- A sense of Lump in the inside of the anal canal or rectum.
- Bright red blood coming separately or on the outside of the stool.
- Unexplained Anemia, Weight loss, Fever.
- Being older in age (more than 45 or 50 years old).
Any Blood with a stool at the age of 45 or more should be carefully investigated. Ask your doctor about the probable investigation you need.
How your doctor will investigate the cause?
Your doctor will perform several tests to investigate the cause of the blood outside the stool. The main tests are:
Your doctor may perform a rectal examination by:
- Inspecting of the outside of the anus.
- Inserting a gloved finger into the anal canal and the rectum to feel for lumps or any abnormalities.
- Anoscopy: a rigid tube is inserted to visualize the anal canal and rectum (performed in the doctor’s office and doesn’t require sedation).
A flexible tube is inserted to examine the lower part of the colon (Anal canal, rectum, and sigmoid colon).
the advantages of sigmoidoscopy is being less painful, doesn’t require intensive preparation nor sedation. But it cannot visualize the entire colon.
Colonoscopy is just like sigmoidoscopy but it has the advantage of screening the entire colon.
Your doctor may require extra investigations such as stool analysis, complete blood picture, abdominal Computed Tomography (CT), or STD testing.
When to see your doctor?
If your experience blood on the outside of the stool you should see your doctor when:
- Unkown, or undiagnosed cause of bleeding into the stool.
- Large amounts of bleeding in the stool.
- Change in frequency or consistency of your bowel movements.
- Abnormal abdominal pain.
- feeling very tired.
- Unexplained anemia, weight loss, or fever.