Common Colon Diseases and How They Are Diagnosed

Colorectal polyps are abnormal growths that develop on the lining of the colon or rectum. Most do not cause symptoms and are often discovered during screening colonoscopy. If polyps are found, they can frequently be removed during the same procedure and examined for signs of cancer.

Colorectal cancer develops when abnormal cells grow uncontrollably in the colon or rectum. Early-stage disease often causes few or no symptoms, making screening and investigations such as colonoscopy important for early detection.

Diverticular disease occurs when small pouches, known as diverticula, form in the wall of the colon. Many people remain symptom-free, but these pouches can become inflamed or infected, resulting in a condition called diverticulitis.

Inflammatory bowel disease (IBD) refers to chronic conditions such as ulcerative colitis and Crohn's disease that cause ongoing inflammation of the digestive tract. The condition typically follows a relapsing and remitting course, with periods of flare-ups and remission.

Infectious colitis is inflammation of the colon caused by bacterial, viral or parasitic infections. It is usually an acute condition and may require investigation to identify the underlying infection.

Ischaemic colitis occurs when blood flow to part of the colon is reduced, limiting the oxygen supply to the affected tissue. It is more commonly seen in older adults and those with underlying vascular disease.

Your colon doctor will ask about your symptoms, bowel habits, medical history, family history and any previous digestive conditions. This is usually followed by a physical examination, which may include an abdominal examination and a digital rectal examination depending on your symptoms.

Blood tests may identify signs of infection, inflammation or anaemia caused by chronic blood loss. They also provide useful information about your general health before additional investigations.

Stool tests can detect hidden blood, infection or inflammatory markers that help identify possible causes of bowel symptoms. Depending on the findings, further investigations may still be required.

A colonoscopy is one of the most comprehensive investigations for examining the colon. Using a flexible camera, your colorectal surgeon can inspect the lining of the colon, identify abnormalities, remove polyps and obtain tissue samples for laboratory analysis during the same procedure.

Imaging tests such as computed tomography (CT) scans or magnetic resonance imaging (MRI) may be recommended to evaluate inflammation, complications or suspected tumours. These investigations also help determine the extent of disease and assist with treatment planning where necessary.

If an abnormal area is identified during colonoscopy, a small tissue sample may be collected for microscopic examination. A biopsy helps confirm the diagnosis and distinguish between inflammatory, infectious and cancerous conditions.