What Is Rectal Bleeding?

Overview

Rectum is the end part of the large intestine (colon).  It is a long tube that includes the colon, rectum and anus. This is the area where the journey of the food from the gastrointestinal tract stops, food waste is passed from colon to the rectum. It is collected in the rectum until the nerve trigger happens for the urge to pass stool (poop).

Rectal bleeding is the condition when blood is seen on the stool or in the toilet or on toilet paper after passing the stool. This may be a symptom of a serious underlying disease condition. Rectal bleeding can be present in different disease conditions, some are haemorrhoids, anal fissures, inflammatory bowel disease (IBD) and colorectal cancer.¹

Gastrointestinal tract starts from the mouth and ends with the anus. When the bleeding occurs it is important to rule out from where the gastrointestinal bleeding is coming, upper gastrointestinal tract or lower gastrointestinal tract.

Causes of rectal bleeding

The source of bleeding can be identified by the colour of the blood in the stool. Black or tarry colour stool indicates bleeding from the upper gastrointestinal tract. Bright red or fresh blood indicates bleeding from the lower gastrointestinal tract, i.e. colon and rectum. Some of the common causes are: 

• Haemorrhoids: It is also known as piles, the condition in which the veins that are present inside or outside the anus and rectum are enlarged and swollen. They are very painful, uncomfortable and they cause rectal bleeding.They occur due to  various reasons and some are; weight gain, during pregnancy, straining for stool for a longer time and constipation. 
• Anal fissure: Anal fissure is a crack or small tear formed in the lining of the anal canal. It is painful and causes rectal bleeding while straining to pass stool. Anal fissure caused due to the passage of hard stool. They can occur suddenly and gradually, but can also heal quickly and slowly.²
• Inflammatory bowel disease (IBD): It is a group of disorders that causes chronic inflammation and pain of the tissues in the intestines.
  • Crohn’s disease: It is a condition which causes inflammation of the tissues of the digestive tract, which leads to abdominal pain, diarrhoea, fatigue, weight loss and malnutrition. Crohn’s disease can affect any area of the digestive tract but most commonly affects the small intestine.¹
  • Ulcerative colitis: In this condition the inflammation and ulcers occur on the lining of the large intestine (colon and rectum). They cause diarrhoea, abdominal pain, weight loss and rectal bleeding. This occurs gradually. The exact cause is unknown, but some of the possible conditions that may aggravate the situation is immune system malfunction, where the immune system fights its own cells rather than fighting the virus or bacteria.³
• Diverticulitis: Small bulging pouches that form in the lining of the digestive system is known as diverticula. They are commonly found in the lower part of the large intestine, the occurrence of diverticula is known as diverticulosis. When the pouches are infected it becomes inflamed, this condition is known as diverticulitis. It causes severe abdominal pain, fever, nausea, constipation or diarrhoea. 
• Sexually transmitted infections (STIs): Sexually transmitted infections are caused by bacteria, viruses or parasites. They can be transmitted from person to person contact through blood, semen or vaginal and other bodily fluids. STIs can also be transmitted to infants during pregnancy or during childbirth, they can be spread through blood transfusion or sharing used needles.⁴
• Peptic ulcer: Peptic ulcers are that develop an open sore on the inside of the stomach and on the upper part of the small intestine. The digestive tract is coated with a mucus layer that protects against the acid, but when the level of the acid secreted is increased or if the level of the mucus is decreased, this can cause the ulcer. This can lead to symptoms like burning pain in the stomach, heartburn, nausea and dark blood in the stools.⁵
• Polyp: Colon polyps are small growth forms on the inside of the lining of the large intestine (colon). Polyps are a type of tumours that are a mass or cluster of abnormal cells. Genetic mutation is considered as the main cause of colon polyps, the changes in the DNA sequence that happens during cell division can cause genetic conditions. DNA (deoxyribonucleic acid) gives the instruction to the body how to form and function. Polyp leads to iron deficiency anaemia, fatigue and blood in stool.^6,7
• Colon cancer: Colorectal cancer develops in the colon, it develops from certain polyps that appear in the inner lining of the colon. This condition can lead to severe abdominal pain, blood in the stool, nausea, unexplained weight loss, bloating and shortness of breath.⁸

Symptoms of rectal bleeding

These are some common symptoms that appear with rectal bleeding and should be consulted by a healthcare provider for further examination.¹ 

• Bright red blood seen in the stool or on the toilet paper after wiping
• Change in colour of the stool
• Pain while passing or straining for stool
• Weight loss
• Fatigue, decrease in blood pressure

Diagnosis

The gastroenterologist is the doctor who specialises and treats disease conditions relating to gastrointestinal tract. The doctor may ask many questions regarding the symptoms the patient feels, the appearance of the blood in the stool, about any medical history the person has. These all help in narrowing down the diagnosis.

• Complete blood test: This is a blood test used to find out the red blood count, haemoglobin, white blood cells.
• Stool culture: It is a test where the patient's stool is taken for examination under a microscope to  find any organisms that are causing gastrointestinal disease. 
• Digital rectal examination: This test examines the lower rectum and anus. This also examines the prostate gland in men and people assigned male at birth (PAMAB)
• Sigmoidoscopy: A flexible sigmoidoscopy is a partial colonoscopy where it examines the lower part of the large intestine, especially the lower part of the colon, rectum and anus. In this a flexible tube with a camera attached at the end is inserted through the anus
• Colonoscopy: Colonoscopy is the examination where a flexible tube with camera at the end is inserted into the body to examine the large intestine, colon, rectum and anus. This helps in diagnosing inflammatory bowel disease and colon cancer.
• Virtual colonoscopy: It is also known as computerised tomography, where a CT scanner is used to produce pictures of colon and rectum

Treatment

Treatment for rectal bleeding depends on the underlying disease condition causing it. Depending on the condition the doctor may suggest medication or any surgical procedure.

FAQs

When should I consult a doctor?

If a person is having severe abdominal pain, bleeding continues to be seen on the stool, pain while passing stool, fatigue is present and sudden weight loss, then should consult the doctor as soon as possible.

Can rectal bleeding be harmless?

Most commonly the rectal bleeding is not life threatening, but in some cases it can be a severe underlying disease condition, so it's better to find out the cause for the rectal bleeding by consulting a doctor.

What is the treatment for rectal bleeding?

Rectal bleeding can occur for so many reasons, the treatment given by the doctor will be according to the underlying disease condition that is causing the bleeding. Drinking a lot of water, using ointments or suppositories to soften the stool can help in reducing the symptoms.

Can rectal bleeding be left untreated?

Rectal bleeding should not be left untreated as loss of blood for a long time can be life threatening. Diagnosing the underlying disease condition is important for proper treatment.

Does every gastrointestinal tract disease condition have the same type of bleeding?

Upper gastrointestinal tract disease condition causes black blood on the stool. The lower gastrointestinal tract disease condition has bright red blood on the stool.

Summary

Rectum is the end part of the large intestine (colon), it is a long tube that includes colon, rectum and anus. Rectal bleeding is the condition when blood is seen on the stool or in the toilet or on toilet paper after passing the stool. This may be a symptom of a serious underlying disease condition. Rectal bleeding can be present in different disease conditions, some are haemorrhoids, anal fissures, inflammatory bowel disease (IBD) and colorectal cancer. The source of bleeding can be identified by the colour of the blood in the stool. Black or tarry colour stool indicates bleeding from the upper gastrointestinal tract. Bright red or fresh blood indicates bleeding from the lower gastrointestinal tract. Treatment for rectal bleeding depends on the underlying disease condition causing it.