Bloody stools is an alarming symptom, especially if it persists beyond one or two days. If the bleeding occurs lower down the intestinal tract, the blood can be visible as red-coloured or stained stools. Other times, blood in the stools appears as dark-coloured or black stools if the source of blood is further up the gastrointestinal tract. A majority of cases of bloody stools are attributed to non-serious conditions like hemorrhoids. Yet, bloody stools can also be a sign of other severe situations like colon cancer. Not knowing the cause of bloody stools can be greatly distressing, thus it is useful to be able to recognise the tell-tale signs of the common hemorrhoid versus a more worrying condition like colon cancer.
Common symptoms of hemorrhoids and colon cancer
Besides bloody stools, other common symptoms that hemorrhoids and colon cancer share can result in them being mixed up. These include:
- Rectal bleeding
- Feeling of incomplete bowel movement
Symptoms of hemorrhoids
Having a basic understanding of hemorrhoids is crucial to distinguishing it from cancer. Hemorrhoids (also called piles) is the condition of swollen veins in the anus, lower rectum or just outside the anal opening. As such, most of the symptoms are localised at the anal area – there should not be any symptoms affecting the digestive processes per se. Here are some symptoms of piles that should not be present in a cancer like colon cancer:
- Itching of the anal area
- Pain in the anal area, especially during bowel movement
- Bright red blood in stools
- Lump outside the anus (only for external hemorrhoid)
Symptoms of colon cancer
On the other hand, colon cancer or colorectal cancer is a condition where abnormal cell growth occurs in the colon (large intestine), forming a tumour. Due to its location in the intestine, the tumour often affects gastrointestinal functions. However, the symptoms of colon cancer may not arise until it has advanced to a later stage. The following are some signs you should look out for that commonly occur in colon cancer patients, but that don’t occur for hemorrhoids:
- Changes to bowel movement, e.g. diarrhoea or constipation
- Nausea, vomiting, or weight loss with no apparent cause
- Abdominal distension (swelling of the belly) – a sign of bowel obstruction
- Gastric pain symptoms
How can your doctor check the cause of your bloody stools?
Often, symptoms alone are not enough to give you a complete diagnosis. Doctors will combine your reported symptoms with your health history and risk factors to decide if further tests need to be conducted to rule out other health conditions. Sometimes, the situation is not so clear-cut, especially if the presence of one condition serves as an aggravating factor for the other, as it has been found to occur.
If you have been referred to a gastroenterologist, they may conduct one of several tests to find out more about the condition you have. These may include:
- Colonoscopy: A type of endoscopy where a long thin tube with an attached camera is inserted through the rectum to examine the lower intestinal tract.
- Stool sample test: A series of tests performed on a sample of faeces.
- Biopsy: Collection of a small tissue sample to test for cancer.