Rectal Bleeding

What Is Rectal Bleeding?

Rectal bleeding is a symptom of a disease rather than a disease itself. It can occur as the result of a number of different conditions, some of which may be life-threatening.

 

The most common cause of rectal bleeding is hemorrhoids. However, more serious causes are possible. So while the cause may not turn out to be serious, it is still important to locate the source of the bleeding.

 

It is important to see your doctor if you have rectal bleeding and:

 

The Link Between Rectal Bleeding and the Digestive Tract

The digestive or gastrointestinal (GI) tract includes the:

 

Rectal bleeding can come from one or more of these areas. For example, bleeding may come from a small area, such as an ulcer on the lining of the stomach, or from a large surface, such as an inflammation of the colon.

 

Rectal bleeding can sometimes occur without the person noticing it. This type of bleeding is called occult, or hidden, bleeding. Fortunately, simple tests can detect occult blood in the stool.

 

What Causes Rectal Bleeding?

Common causes of rectal bleeding include:

 

In the lower digestive tract, the large intestine and rectum are frequent sites of bleeding. Hemorrhoids are the most common cause of visible blood in the digestive tract, especially blood that appears bright red. Hemorrhoids are enlarged veins in the anal area that can rupture and produce bright red blood, which can then show up in the toilet or on toilet paper. If red blood is seen, however, it is essential to exclude other causes of rectal bleeding, since the anal area may also be the site of cuts (fissures), inflammation, or cancer.

 

Benign (noncancerous) growths or polyps of the colon are common, and are thought to be possible forerunners of cancer. These growths can cause either bright red blood or occult bleeding (hidden bleeding). Colorectal cancer is the third most common cancer in the United States, and often causes occult bleeding at some point, but not necessarily visible rectal bleeding.

 

Inflammation from various causes can produce extensive bleeding from the colon. Different intestinal infections can cause inflammation and bloody diarrhea. Ulcerative colitis can produce inflammation and extensive surface bleeding from tiny ulcerations. Crohn's disease of the large intestine can also produce rectal bleeding.

 

Diverticular disease caused by pouches in the colon wall can result in massive bleeding.

 

Finally, as a person gets older, abnormalities may develop in the blood vessels of the large intestine (this is called angiodysplasia). This may result in recurrent rectal bleeding.

 

People taking blood-thinning medications (such as warfarin) may have rectal bleeding, especially if they take drugs like aspirin.

 

Common Symptoms of Rectal Bleeding

The symptoms of rectal bleeding depend upon the site and severity. Some common symptoms include:

 

Some symptoms might indicate whether the bleeding is acute (short-term) or chronic (long-term). Symptoms of acute rectal bleeding include:

 

Symptoms of chronic rectal bleeding include:

 

If bleeding is coming from the rectum or the lower colon, bright red blood will coat or mix with the stool. The stool may be mixed with darker blood if the bleeding is higher up in the colon or at the far end of the small intestine. When there is bleeding in the esophagus, stomach, or duodenum, the stool is usually black or tarry.

 

If bleeding is occult (hidden), you might not notice any changes in stool color.

 

If sudden massive rectal bleeding occurs, a person may feel weak, dizzy, faint, short of breath, or have crampy abdominal pain or diarrhea. Shock may occur, with a rapid pulse, drop in blood pressure, and difficulty in producing urine. The person may become very pale.

 

If bleeding is slow and occurs over a long period of time, a gradual onset of fatigue, lethargy, shortness of breath, and pallor (a pale appearance) from the anemia will result. The term "anemia" means that there is a lack of the blood's iron-rich substance, hemoglobin.

 

How Is Rectal Bleeding Diagnosed?

It's important to locate the site of the rectal bleeding. A complete history and physical examination are an essential part of making a diagnosis. Symptoms such as changes in bowel habits, stool color (from black to red, for example) and consistency, and the presence of pain or tenderness may tell the doctor which area of the GI tract is affected.

 

Since eating iron-rich foods, bismuth (Pepto-Bismol^®), or foods such as beets can give the stool the same appearance as bleeding from the digestive tract, a doctor must test the stool for blood before offering a diagnosis. A blood count will indicate whether the person is anemic and also will give an idea of the extent of the rectal bleeding and how chronic it may be.

 

Endoscopy is a common diagnostic technique that allows the doctor to see the site of rectal bleeding. Because the endoscope can detect lesions and confirm the presence or absence of bleeding, doctors often choose this method to make a diagnosis of acute rectal bleeding. In many cases, the endoscope can be used to treat the cause of rectal bleeding as well.

 

The endoscope is a flexible instrument that can be inserted through the mouth or rectum. It allows the doctor to see into the esophagus, stomach, duodenum, colon, and rectum. The endoscope also allows the doctor to collect small samples of tissue (biopsies), to take photographs, and to stop the bleeding.

 

Small bowel endoscopy, or enteroscopy, is a procedure that uses a long endoscope. This endoscope may be used to pinpoint unidentified sources of rectal bleeding in the small intestine.

 

A new diagnostic instrument called a capsule endoscope is swallowed by the person. The capsule contains a tiny camera that transmits images to a video monitor. It is used most often to find bleeding in portions of the small intestine that are hard to reach with a conventional endoscope.

Several other methods are available to locate the source of rectal bleeding. These can include:

 

In general, barium x-rays are less accurate than endoscopy in locating bleeding sites. Some drawbacks of barium x-rays are that they:

 

Another type of x-ray, called a CT (computed tomography) scan, is particularly useful for finding inflammatory conditions and cancer.

 

Angiography is a technique that uses dye to highlight blood vessels. This procedure is most useful in situations when the person is acutely bleeding. When this happens, the dye leaks out of the blood vessel and identifies the site of bleeding. In some situations, angiography allows medicine to be injected into the arteries that may stop the rectal bleeding.

 

Radionuclide scanning is a noninvasive screening technique used for locating sites of acute rectal bleeding, especially in the lower GI tract. This technique involves an injection of small amounts of radioactive material. Then a special camera produces pictures of organs, allowing the doctor to detect the site of a GI bleed.

 

Treatment for Rectal Bleeding

Endoscopy is the primary diagnostic and therapeutic procedure for most causes of rectal bleeding. Active bleeding from the upper GI tract can often be controlled by injecting chemicals directly into a bleeding site with a needle introduced through the endoscope. A physician can also cauterize (treat with heat) a bleeding site and surrounding tissue with a heater probe or electrocoagulation device. These devices are also passed through the endoscope. Laser therapy is useful in certain specialized situations.

 

Once rectal bleeding is controlled, medicines are often prescribed to prevent the bleeding from coming back. Medicines are useful primarily for H. pylori infections, esophagitis, ulcers, other infections, and irritable bowel syndrome (IBS). Medical treatment of ulcers -- including the elimination of H. pylori -- to ensure healing, as well as maintenance therapy to prevent the return of ulcers, can also lessen the chance of recurrent bleeding.

 

Removing polyps with an endoscope can control bleeding from colon polyps. Removing hemorrhoids by banding or various heat or electrical devices is effective in people who suffer hemorrhoidal bleeding on a recurrent basis. Endoscopic injection or cauterization can be used to treat sites of rectal bleeding throughout the lower intestinal tract.

 

Endoscopic techniques do not always control rectal bleeding. Sometimes, angiography may be used. However, surgery is often needed to control active, severe, or recurrent bleeding when endoscopy is not successful.