The presence of blood in the stools can be alarming and distressing for most people, especially those concerned about bowel cancer and colorectal cancers. It is important to consider undergoing a colonoscopy as part of colorectal cancer screening. Suspecting colorectal cancers, such as colon cancer, can lead to further anxiety in patients.
Early detection through colonoscopy is crucial in identifying and removing precancerous polyps. When there are high levels of fresh red blood, it can be even more worrisome to our patients as it may indicate high risk for colorectal cancers. Blood can originate from the upper intestinal tract (i.e., stomach or esophagus) to the colon and anus, which can be a potential sign of bowel cancer or colorectal cancers.
It is important to undergo a colonoscopy for early detection and effective colorectal cancer treatment. If bleeding occurs in the upper digestive tract, stools can appear black and tarry, which can be a symptom of bowel cancer or colorectal cancers. It is important to consult a doctor and consider undergoing a colonoscopy to screen for colon cancers.
If bleeding originates from the lower gastrointestinal tract, such as the bowel, it is important to consider the possibility of colorectal cancers.
In such cases, the blood typically appears red and fresh, indicating that it has not undergone digestion. To diagnose or treat these conditions, a colonoscopy or surgery may be necessary.
Potential Causes of Blood in the Stools
There are several potential causes of blood in the stools, including colorectal cancer and colon cancer. It is important to undergo regular colonoscopy screenings to detect any abnormalities in the bowel. Some of the likely causes include:
- Piles or hemorrhoids
- Tear in the anal lining (anal fissure)
- Inflammatory bowel diseases (this can include Crohn’s disease or ulcerative colitis)
- Inflammation or infection of the intestines (colitis)
- Diverticular disease (small out pouches that form in the walls of the colon that can bleed)
- Upper gastrointestinal tract ulcers (an open ulcer in the lining of the duodenum, stomach, or the small intestine’s upper end)
- Esophageal varices (i.e. dilated veins in the esophagus)
If the patient has bleeding per rectum (PR), the initial workup will include history, physical examination, colonoscopy, surgery, and bowel screening. Other crucial symptoms and history to note include:
- Weight loss
- Nature and quantity of the bleeding (Note: Bright red and fresh blood typically originates from the lower gastrointestinal tract. If the patient has colorectal cancer, blood loss may be minimal. In other cases, it is not visible to the naked eye – occult blood.)
- Change in bowel habit (This includes the type of the stool and the frequency of the defecation. Some colorectal cancer patients can experience diarrhea or constipation).
- Anal symptoms (This includes persistent pain or masses at the anus).
- Incomplete emptying or the feeling like you need to pass motion, i.e., tenesmus (This symptom can indicate cancer of the rectum).
- Trauma, medical history, the use of aspirin (and other medications) and previous radiation treatment (Prior radiotherapy may lead to a condition of bleeding that can manifest many years after the treatment).
- Family history of polyposis (i.e., familial adenomatous polyposis (FAP))
Concerning general examination findings include weight loss, pallor, and abdominal symptoms related to colorectal cancer, bowel, colon cancer, and colonoscopy. A rectal and perianal examination may also be done.
Additional Evaluation
To screen for colorectal cancer, a colonoscopy might be requested to check for anemia. Additionally, a full blood count might be requested to monitor the effects of chemotherapy. If the anemia is caused by blood loss from colorectal cancer, it typically results in iron deficiency anemia.
This can be treated with chemotherapy for cancers. Iron levels in the blood can be easily checked with a screening test, and iron supplements prescribed if indicated. Additionally, regular exercise has been shown to improve treatment outcomes for individuals undergoing colonoscopy.
If the doctor suspects colorectal cancer, a colonoscopy with possible biopsies is done as part of the screening process. This helps determine the need for surgery or chemotherapy.
Colorectal Cancer
Colorectal cancer, also known as colon cancer, affects the colon and rectum. It is important to undergo regular colonoscopies to detect any tumors early. If diagnosed with colon cancer, treatment options may include chemotherapy.
When people eat food, it enters their colon where water is absorbed and food residue is converted into faeces by bacteria. This process is important for the prevention of colorectal cancer, one of the most common cancers affecting people.
Regular colonoscopy screenings can help detect and prevent this type of cancer. The colon’s terminal part is the rectum. It stores waste before expelling it through the anus.
Colorectal cancer can develop when polyps form on the rectum and inner walls of the colon. Colonoscopy is a crucial screening method to detect these precancerous growths and prevent the development of cancers.
These benign lumps, also known as tumors, are common in people 50 years old and above. They can occur in various types of cancers, including colon cancer and colorectal cancer.
However, there are certain types of polyps, such as colon polyps, that can progress into cancers and should be removed when detected to prevent tumor formation. Malignant polyps typically have certain characteristics.
- They are greater than 1 cm in diameter
- Multiple polyps
- Sessile polyps (i.e., those without a stalk)
- High grade cellular abnormalities
In its early stage, cancer cells will be confined to the colon. This is why tumor screening is crucial in detecting cases of cancer early on. When undetected, colorectal cancer can develop and extend into the colon’s lumen, leading to the growth of tumors and progression to advanced stages of the disease. Colorectal cancer can also spread and invade the colon wall, posing a risk to people with tumors.
- Entering the bloodstream (it can also travel to the liver and form secondary malignant deposits)
- Invade neighboring organs and intestines
- Entering the lymphatic system (it can travel into the neighboring lymph glands)
Risk Factors
Common colon cancer risk factors include:
- Age. Women and men aged 50 years (and above) have a higher risk of colon cancer.
- Personal History. Individuals diagnosed with colorectal cancer in the past or those with colorectal polyps have a higher risk of experiencing a possible recurrence. As such, regular screening is recommended.
- Family History. Some people develop a rare condition known as familial polyposis (in similar cases, colorectal polyps can develop at an early age). These individuals have a very high chance of developing colon cancer (80 to 100%). Those with relatives with colorectal cancer or polyps also have a higher risk of developing the condition. However, it is lower compared to those people with familial polyposis.
- Ulcerative Colitis. This disease that affects the bowels might lead to inflammation and cancer in the long term. People with ulcerative colitis are also at a higher risk of developing colon cancer.
- Obesity and Sedentary Lifestyle. These two interrelated factors can increase one’s chance of developing colon cancer. However, physical activity has been known to reduce the risk by improving the movement of waste (feces) in the colon.
- Dietary Habits. Research has shown that certain dietary factors can increase one’s risk of developing colorectal cancer. Some of the dietary habits include alcohol, processed and red meat, meat that are cooked at high temperature.
Despite awareness of the risk factors, the exact cause of colon cancer, a tumor that affects many people, is still unknown after many years. Surprisingly, an estimated 50% of people with colon tumor have no known risk factors for years.
Screening for Colon Cancer
Screening tests can help doctors find colon cancer or polyps before symptoms can manifest. These tests are crucial for identifying tumors and reducing the risk of developing colon cancer over the years.
Early detection of colon cancer has been known to improve the success rate of treatment for people at risk of developing tumors within a few years. The following screening tests may be used to detect colon cancer, polyps, and other abnormalities in people at risk of developing a tumor.
- Fecal Occult Blood Test (FOBT). At times, cancer or polyps can cause bleeding. A Fecal Occult Blood Test is done to find tiny amounts of blood in the stool. If blood is found in the stools, other tests can be conducted to find the source. Colon cancer is not the only condition that can cause blood to appear in the stools. Hemorrhoids and other benign conditions can also cause these symptoms.
- Sigmoidoscopy. A small lit tube (sigmoidoscope) is used to examine the rectum as well as the colon’s lower part. Doctors may also remove polyps that are found.
- Colonoscopy. Using a colonoscope (a flexible and long tube with a camera), doctors can examine the insides of the colon and the intestine. Polyps that are found may also be removed during colonoscopy.
- Computed Tomography (CT) scan of the Colon. A CT machine will be used to take images of the rectum and the colon. This is done to check for tumors and polyps.
- Double-contrast Barium Enema. This procedure involves filling the rectum and the colon with barium (a white liquid that can enhance X-ray pictures). This will allow polyps (and anything else out of the ordinary) to be clearly seen in the scans.
Colorectal Cancer Assessment
Not all symptoms of colon cancer will prove the presence of a tumor. However, it is important for people to be aware of the risk and seek medical attention if they experience any symptoms. The patient’s family and personal history of people will be looked into to assess the risk of developing a colorectal cancer tumor.
A physical examination will also be done to determine the cause of the symptom(s), including assessing the risk of tumor development and colon cancer or colorectal cancer.
If abnormalities like polyps are found, it can be removed for a biopsy during sigmoidoscopy or colonoscopy. This is especially important for people at risk of colorectal cancer as it helps detect any tumor formation. A pathologist will examine the colon biopsy using a microscope to check for the presence of cancer cells. This procedure is important in assessing the risk of cancer in people.
If the biopsy indicates the presence of cancer in the colon, doctors will conduct additional tests to determine the stage of the cancer. This is important to assess the risk and provide appropriate treatment options for people affected by this condition. The stage of colon cancer will be determined by certain factors such as the risk of spread, whether the tumor has invaded nearby tissues, and other relevant considerations for people affected by this disease.
Colorectal Cancer Stages
The stages of colorectal cancer are:
- Stage 0. The cancer is located in the rectum or colon’s innermost lining. The cancer cells have not developed and spread (also known as pre-cancer).
- Stage I. In this stage, the tumor has already grown into the colon or rectum’s inner wall (but not through the wall).
- Stage II. In this stage, the tumor has grown through or deep into the colon or rectum’s wall. It may have also invaded the tissues nearby. However, the cancer cells have not spread to the lymph nodes yet.
- Stage III. In this stage, the tumor has already spread to the lymph nodes nearby. However, the cancer cells have not spread to the other parts of the body yet.
- Stage IV. In this stage, the cancer has spread to the other parts of the body (i.e., the lungs or the liver).
Recurrence. This refers to cancer that has been treated but has returned after sometime. The cancer can return in the rectum or colon or other parts of the body.
Treatment and Care
- Surgery. The tissues that have the tumor (including the lymph nodes and the tissue nearby) can be removed through surgery.
- Chemotherapy. Chemotherapy involves using drugs to destroy or shrink the cancer cells. The drugs will enter the bloodstream and travel to the cancer cells found in the body.
- Targeted Cancer Therapy. When the cancer has spread, targeted therapy may be given. These are drugs (and other substances) that can stop or reduce the spread of cancer.
- Radiation Therapy. Also called radiotherapy, this makes use of high-energy rays to destroy the cancer cells in the areas affected.
