A Simple Guide to Blood in Stools, Related Diseases and Use in Disease Diagnosis

Blood in the Stools

What is Blood in the Stools?

Blood in the stools can be in the form of red blood in the stools (hematochezia) or black stools (melena).

Red Blood in the Stools or Hematochezia is bleeding from the lower gastrointestinal tract with red fresh blood in the stools.

Blood in the Stools is usually bright red.

Hematochezia usually presents as minor bleeding that is important because it may have come from a rectal or colonic cancer.

Direct questions regarding the frequency, amount, and duration of hematochezia should allow the examiner to determine whether the patient is bleeding dangerously or minor bleeding.

Black Melena stools are shining black in color and sticky (tarry).

The black color of the stools is believed to be oxidation of the iron from the red blood cells in the intestines usually more than the 14 hours from its origin in the upper part of the digestive tract.

Typically the stools have a black color with a red tinge at the edges and are soft and almost slimy.

Other substances such as iron or bismuth can turn the stool black but not shining.

A melenic stool contains blood and usually means upper gastrointestinal hemorrhage,

It takes 50 ml or more of blood in the stomach to turn stools black.

One to two liters of blood given orally will cause bloody or tarry stools for up to 5 days.

The first such black stool usually appears within 4 to 20 hours after ingestion.

Thus a melenic stool is indicative of recent bleeding but does not indicate the presence or rapidity of bleeding at the time of passage.

Hematochezia usually comes from a colonic site although blood rapidly transported from the upper gastrointestinal tract can be red when passed.

In older patients, massive lower intestinal hemorrhage is frequently caused by a bleeding diverticulum or an arteriovenous malformation.

Very rapid upper gastrointestinal bleeding less than 14 hours often from an arterial site in a peptic ulcer may cause hematochezia.

What are the Causes of Blood in the Stools?

Causes that can make a person pass blood in the stools are:

1. Cancer of the colon and rectum

2. Bleeding hemorrhoids

3. Ulcerative colitis

4. Diverticulitis

5. peptic ulcers

6. Injury in the anus or rectum

7. Bleeding diseases

How is Blood in the stools diagnosed?

1. Physical examination of the anal region for piles and injuries

2. Proctoscopy for piles

3. Sigmoidoscopy for rectal tumors

4. Colonoscopy for rectal and colon cancers and polyps

5. Full blood count for bleeding diseases or blood cancers

6. Stool culture for bacterial, viral and parasitic infections

7. Test to see if the blood clots normally, such as PT or PTT

8. Colon polyp or ulcer biopsy

TABLE OF CONTENT
Chapter 1 Blood In Stools

Chapter 2 Disease Diagnosis

Chapter 3 Hemorrhoids

Chapter 4 Cancer of Colon

Chapter 5 Ulcerative Colitis

Chapter 6 Colon Polyps

Chapter 7 Diverticulitis

Chapter 8 Intussusception

Chapter 9 Dysentery

Epilogue