Rectal Bleeding

rectal bleeding What is rectal bleeding?

The term rectal bleeding, means any blood that is passed out when you go to the toilet to pass faeces. However, not all bleeding that is passed out actually comes from the rectum. The blood can come from anywhere in the gut (the gastrointestinal tract). The more correct term is gastrointestinal tract bleeding, often abbreviated to GI bleeding.

What do you understand by gut?

The gut (gastrointestinal tract) starts at the mouth and ends at the anus. Anything we eat or drink travels down the mouth, through the esophagus, stomach and then passes through the small intestines. The small intestine is where food is digested and absorbed. Undigested food, water and waste products are then passed into the large intestine (sometimes called the large bowel). Some water and salts are absorbed into the body from the large intestines. It then gets stored in the rectum from where they are passed out from the anus.

How do you diagnose rectal bleeding?

When a patient has bleeding the doctor assesses rectal bleeding by the following factors:

  • Severity of the bleeding, range from a mild, trickle to a massive life-threatening severe bleed (a severe haemorrhage). Majority of cases comprise of mild and intermittent bleed in which all blood test are done as an outpatient clinic, however, large amount of bleeding requires urgent hospitalization.
  • Sometimes bleeding is so mild (like a slight trickle) that it is not noticeable, however, a test of faeces can detect even small amounts of blood.

  • Site of the bleeding, can be from anywhere in the GI tract. Generally if the bleeding isfrom the anus or low down in the rectum , colour of blood tends to be bright red and fresh and is not mixed with faeces but is noticed after passing faeces, or streaks of blood covering faeces . Bleeding from colon is associated with blood which is mixed up with faeces (motions or stools). The blood may be a dark red. However, if the bleeding is brisk, one can may still get bright red blood not mixed up too much with faeces. Bleeding from the stomach or small intestine includesblood that is altered and dark and mixes with faeces. This can make your faeces turn a black or plum colour - this is called melaena. It is a medical emergency, and one should tell a doctor immediately if you suspect it.
  • The cause of the bleeding is important to find out, for which the doctor needs to ask questions like, history of diarrhea, pain, weight loss, or other relevant symptoms. The doctor would also like to examine the anus.

The main causes of rectal bleeding/ GI tract bleeding include:

  • Haemorrhoids (piles) are swellings in the anus and lower rectum. There are a network of small veins (blood vessels)inside the mucus lining of the anus and lower rectum, which when it gets engorged with blood, the overlying tissue may then form into one or more swellings called as haemorrhoids. Haemorrhoids, which are small, are generally painless and present with bleeding, but larger haemorrhoids present with mucous discharge, pain, irritation and irritation.
  • Anal fissureis a small tear of the skin of the anus. Although the tear is usually small (usually less than a centimetre), it is very painful as the anus is very sensitive. Bleeding from anal fissure is less, but seen as bright red and stains the toilet tissue.
  • Diverticula, is a small pouch with a narrow neck that sticks out from the wall of the gut. They can develop on any part of the gut (intestines), but usually occur in the colon. Several diverticula may develop over time. They may occasionally bleed and you may pass some blood via your anus. The bleeding is usually abrupt and painless and sometimes could be heavy.
  • Crohn's disease is an inflammatory disease of the gut, which flares up from time to time, and symptoms vary from bloody diarrhoea, abdominal pain, and feeling unwell.
  • Ulcerative colitis and other forms of colitis is again an inflammatory condition of the colon and rectum. It presents with diarrhoea mixed with blood.
  • Polyps of the bowel is a small growth that forms on the inside lining of the colon or rectum. Generally develops in older people. They are benign (non-cancerous) and usually cause no problems, however, sometimes a polyp bleeds and can turn cancerous.
  • Cancer of the colon and rectum are common cancers of the older people but sometime can affect younger people. They generally present with bleeding and include pains, anemia, weight loss, diarrhoea or constipation. Cancers of other parts of the gut higher up from the colon sometimes cause rectal bleeding, but these are uncommon.
  • Angiodysplasiais a condition where one can develop a number of enlarged blood vessels within the inner lining of the colon, it generally presents as bleeding, which is, brisk and painless. The blood can range from bright red brisk bleeding, to dark blood mixed with faeces, to melaena.
  • Abnormalities of the gut are known to cause rectal bleeding in young children. For example: volvulus, intussusception, Meckel's diverticulum, and abnormal blood vessel development.
  • Stomach and duodenal ulcersmay bleed. This can cause melaena - where your faeces turn black.
  • Lotof gut infections can cause bloody diarrhoea due to inflammation of the gut, due to infections.

If the patient has rectal bleeding, itís best to see your doctor. If the bleeding is heavy, or if one has melaena,call an ambulance, and see a doctor. If there are symptoms of hypotension like dizziness, collapse or feel generally unwell then consider calling an ambulance, as this might indicate a heavy bleed. However, often the bleeding is mild, which would require an appointment with the doctor .

What tests are required?

The test required by the doctor depends on your history. Generally for rectal bleeding colonoscopy and sigmoidoscopy are required.

Colonoscopy is a test where an operator (a doctor or nurse) looks into the colon. It is composed of a thin, flexible fibreoptic scope, which is passed through the anus into the colon and can be pushed as far as the caecum (where the small and large intestine meet).

Sigmoidoscopy is seeing the sigmoid colon (the final portion of the bowel that is joined to the rectum) with the fibreoptic scope.

Faecal occult blood test (FOB test) detects small amounts of blood in your faeces, which you would not normally see or be aware of. Generally done in cases where rectal bleeding is not apparent.However the FOB test can tell you that the patient is bleeding form the gut , but cannot tell you from where it is bleeding. It can be used as one of the screening test of colorectal cancer (bowel cancer).

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