Rectal bleeding is often seen as bright red blood in stools or as fresh blood after passage of stools . Rectal bleeding can also be recognized in extremely dark stool, ranging in colour from deep red/maroon to black, and sometimes appearing tar-like (melena).
The colour of the blood can often indicate where the bleeding is coming from – rectum , colon , small bowel or upper GI tract. Not all rectal bleeding is visible to the eye. In some cases, rectal bleeding can only be seen by looking at a stool sample through a microscope.
What causes rectal bleeding?
Although rectal bleeding is common, only about one-third of those affected seek treatment. Rectal bleeding can be caused by:
» Anal fissure.
» Anal abscess or fistula.
» Inflammatory bowel disease (IBD).
» Large polyps.
» Colorectal Cancer
What are the tests to evaluate rectal bleeding:
The best test for rectal bleeding depends upon your age, symptoms, and past medical history. These include Digital rectal examination, proctoscopy , sigmoidoscopy or colonoscopy .
Now , we will analyze the most common causes of blood in stools and the treatment options .
What are hemorrhoids?
Hemorrhoids, the most common cause of rectal bleeding, are swollen veins in the rectum (internal hemorrhoids) or the anus (external hemorrhoids). Hemorrhoids, also called piles, can develop because of chronic (long-term) constipation or straining at stools, pregnancy, work strain (heavy lifting), obesity etc.
Hemorrhoid treatment includes addressing the underlying causes, such as treating the constipation or straining habits, or changing work habits if necessary. Sometimes surgery is necessary if the hemorrhoids are large or when conservative treatment like dietary changes and increasing water intake fail to control the symptoms.
What is an anal fissure?
An anal fissure is a split or tear in the lining of the anus, causes bleeding and burning pain after bowel movements. The usual cause is passing a very hard stool. Fissures often improve by themselves, but if they don't, an ointment or medication applied directly to the fissure to relax the muscle can relieve the pain. Surgery may be needed for a chronic or recurrent (returning) fissure or if excessive sphincter spasms prevent the tear from healing on its own.
What is a perianal abscess?
An infection can occur when one of the anal glands becomes blocked. The pocket of pus caused by the blockage is an abscess. The abscess can be drained under local anesthesia . About a third of all perianal abscesses will develop into an anal fistula.
What is an anal fistula?
An anal fistula is a connection between the anus or rectum to the skin around the anus. An anal fistula is caused by an infection in the perianal area, or by inflammatory bowel disease, tuberculosis, or radiation. Others can result from surgery in that area. Anal fistulas require surgery in order to heal.
What are diverticulosis and diverticulitis?
Diverticulosis develops when small pouches (diverticuli) form in weakened sections of intestine lining and protrude through the bowel wall. Diverticuli are a common finding among older people .Diverticulosis is a benign (noncancerous) disorder, but bleeding and infection can occur. Diverticuli generally occur without symptoms, unless they become blocked and infected and cause diverticulitis.Treatment may include a special diet, antibiotics or surgery.
What is inflammatory bowel disease (IBD)?
Inflammatory bowel disease (IBD) is an inflammation (swelling) of the small or large intestine. There are two types of IBD: Crohns’s Disease or Colitis . Treatment of inflammatory bowel disease is critical and may involve a special diet, medication to eliminate or reduce inflammation, and/or surgery.
What are polyps?
A polyp, which looks like a small mushroom, attaches to the lining of the large bowel. Certain polyps are considered precancerous and can develop into cancer if left untreated. Colonoscopy is the procedure to locate and remove polyps to prevent colorectal cancer
The early stages of colorectal cancer may have no apparent symptoms. Regular screening is important—particularly for individuals who are at increased risk. People who have an increased risk of colorectal cancer include those who have a family history of colorectal cancer, and people who have previously had cancer or polyps. Treatment for colorectal cancer may include surgery, chemotherapy and radiation.
Why should we worry about rectal bleeding?
While most rectal bleeding is caused by the non-serious causes mentioned above, bleeding can also be caused by cancerous or precancerous conditions too. Precancerous polyps near the end of the colon can mimic bleeding from hemorrhoids. These are generally present in the colon for years before they become cancerous, and they can be removed very safely from the colon, preventing progression to cancer.
Colon cancer may be diagnosed in patients who have ignored bleeding for years because they assumed it was from hemorrhoids. Polyps and colon cancer become more common with ageing, and thus investigation of bleeding is most important, and is usually most intensive, in patients over the age of approximately 40 to 50 years.
Thus, anyone who notices rectal bleeding should talk to their doctor to determine if an examination is needed.
(Dr. Anoop S Nair is a consultant, gastroenterology, Centre of Excellence for Gastro Sciences, Meitra Hospital, Kozhikode)