Colon Polyps in Singapore

Written & reviewed by the BestDoctors.sg editorial team · Last updated 1 Sep 2026 · General information, not medical advice

Colon polyps are the reason screening is so effective against bowel cancer: finding and removing a pre-cancerous polyp stops a cancer before it ever forms. That’s a rare and powerful opportunity in cancer prevention.

What they are

A polyp is a small growth that develops on the inner lining (the mucosa) of the colon or rectum and projects into the hollow space through which stool passes. Some are flat and barely raised, while others sit on a stalk like a tiny mushroom. Polyps are common, and they become more common with age. The great majority are benign – they are not cancer, and many never cause any trouble at all.

What makes them important is that a minority of polyps can, over a long period, undergo changes in their cells that eventually lead to cancer. This does not happen quickly and it does not happen to most polyps, but because there is no reliable way to tell from the outside which polyp is heading in that direction, the safe approach is to find them and take them out. Removing a polyp before it has any chance to become malignant is one of the few ways doctors can genuinely prevent a cancer rather than simply treat it. This is the whole logic behind bowel-cancer screening.

Types

Polyps are grouped by what they look like under the microscope after removal, and the type matters because it tells the doctor how much attention a polyp deserves.

• Adenomas (adenomatous polyps) are the type that carries cancer potential. They are common, and most colorectal cancers are thought to begin as an adenoma that slowly changes over many years – the so-called adenoma-to-cancer sequence. Even so, only a small share of adenomas ever become cancerous, and removing them interrupts that pathway.
• Sessile serrated lesions are a flatter type that is also considered to carry cancer potential. Because they can be pale and hard to spot, they are important to look for carefully and are removed when found.
• Hyperplastic polyps are usually small and generally carry little or no cancer risk, particularly when they sit in the lower part of the bowel. They are common and typically harmless.
• Inflammatory and other polyps can form in people with long-standing bowel inflammation and are usually benign, though they are still assessed by the doctor.

Larger polyps and those with more advanced cell changes carry more risk than small, simple ones, which is another reason the laboratory examination after removal is so useful – it guides what happens next.

Symptoms

Most polyps cause no symptoms whatsoever. People feel completely well, and the polyp is discovered only because they had a screening test or a colonoscopy for another reason. This silence is exactly why waiting to feel unwell is the wrong strategy – by the time symptoms appear, more may have changed.

When a polyp does cause symptoms, it is usually because it is larger. Possible signs include rectal bleeding or blood in the stool, a change in bowel habit such as looser stools or constipation that persists, or the passage of mucus. These same symptoms can be caused by many other, less serious conditions such as haemorrhoids, but they should never be assumed to be harmless – they always deserve to be checked by a doctor.

Causes and who is at risk

Doctors do not always know why a particular person develops polyps, but several factors are known to raise the chances:

• Older age – polyps become steadily more common as people get older, which is why screening is aimed at adults from midlife onwards.
• Family history – having a close relative who has had polyps or bowel cancer increases risk.
• Inherited conditions – certain genetic syndromes, such as Lynch syndrome and familial adenomatous polyposis, greatly increase the number of polyps and the cancer risk, and call for earlier and closer monitoring.
• Inflammatory bowel disease – long-standing ulcerative colitis or Crohn’s disease affecting the colon raises risk.
• Lifestyle – smoking, a higher body weight, heavy alcohol use, a diet high in red and processed meat and low in fibre, and physical inactivity are all associated with more polyps.

Some of these – age, family history and inherited syndromes – cannot be changed, and they are the reason a doctor may recommend screening. Others are within a person’s control, and improving them supports overall bowel health.

How they are found and diagnosed

Colonoscopy is the key test. Using a thin, flexible tube with a camera, a doctor can examine the whole lining of the colon and rectum, and – crucially – find and remove any polyps in the same session, sending the tissue to the laboratory to be examined. Because it both detects and treats, colonoscopy is considered the most complete test. It usually requires bowel preparation beforehand and some form of sedation.

Other tests play a supporting role. Stool tests such as the faecal immunochemical test look for tiny, invisible traces of blood in a stool sample; they are simple and non-invasive, but a positive result needs to be followed up with a colonoscopy to see what caused the bleeding. CT colonography is a specialised scan that produces detailed images of the bowel and can be an option for people who cannot have a standard colonoscopy, though any polyp it finds still has to be removed by colonoscopy. In Singapore, a gastroenterologist can advise which test suits an individual, often starting from a discussion with a GP or polyclinic doctor.

Why screening matters

Screening is the reason polyps are worth talking about at all. Because polyps grow silently and change slowly, finding and removing them before symptoms appear is what prevents many bowel cancers from ever developing. Singapore encourages bowel-cancer screening for people at average risk from midlife onwards, and reliable information on the current national recommendations is available through HealthHub and organisations such as the Singapore Cancer Society. Anyone unsure about whether and when to be screened should check the current recommendations and speak with a GP, who can weigh personal and family history and point to the right test. See our guides to colonoscopy and health screening for more.

Treatment

Treatment usually means removing the polyp, and this is normally done during the colonoscopy itself – a procedure called a polypectomy. Small polyps can often be lifted off painlessly during the examination, while larger or more awkward ones may need a more involved technique or, occasionally, a separate specialist procedure. The removed tissue is then examined under the microscope, and it is this result – the type of polyp, its size and its cell changes – that guides how soon the next colonoscopy is advised. In this way, treatment and future planning happen together.

Living with it and follow-up

For most people, having a polyp removed is the end of the matter for the time being. Because someone who has had one polyp is a little more likely to form others, the doctor will usually recommend a surveillance colonoscopy after a certain interval. That interval is set individually by the specialist based on what was found – the number, size and type of polyps – so it is important to keep to the timing you are given and to attend follow-up even when you feel completely well.

Alongside surveillance, general bowel-healthy habits support long-term health: eating plenty of fibre from wholegrains, fruit and vegetables, limiting red and processed meat, staying physically active, keeping to a healthy weight, not smoking, and moderating alcohol. These measures do not replace screening, but they support the bowel and overall wellbeing.

When to see a doctor and red flags

Because polyps are usually silent, the most important reason to see a doctor is to be screened at the recommended time – not to wait for a symptom. That said, some symptoms should always be checked promptly, whether or not you are due for screening:

• Blood in the stool or rectal bleeding of any kind.
• A persistent change in bowel habit – looser stools, constipation, or a change in the shape of stools that does not settle.
• Unexplained weight loss.
• Ongoing tummy pain or cramping.
• Tiredness or breathlessness that could come from anaemia (a low blood count from slow bleeding).

None of these symptoms means a person has cancer – they have many causes – but they should never be ignored. A GP or gastroenterologist can assess them, arrange the right tests and provide reassurance or treatment as needed.

Related digestive & liver conditions

• Barrett’s oesophagus
• Oesophageal cancer
• Hiatus hernia
• Gastroparesis (delayed emptying)
• Lactose intolerance
• Jaundice in adults
• Bile duct stones & cholangitis
• Alcohol-related liver disease
• Abnormal liver function tests
• Acid reflux & GERD
• Gallstones
• Gastroenterologists in Singapore
• Colonoscopy
• Virtual Colonoscopy (CT Colonography)
• Colonoscopy Cost in Singapore: Prices, MediSave & Colorectal Cancer Screening

Sources

• NHS — bowel polyps (what they are; benign nature with some cancer potential; symptoms; risk groups; polypectomy; when to see a GP).
• Cleveland Clinic — colon polyps (types – adenoma, hyperplastic, sessile serrated; the adenoma-to-cancer timeline; size and risk; risk reduction from removal).
• Singapore Cancer Society / HealthHub / National Cancer Centre Singapore — bowel-cancer screening (stool testing and colonoscopy; follow-up of a positive stool test); colorectal cancer among the most common cancers in Singapore.