Colorectal cancer, also called bowel cancer, develops in the colon or the rectum. Most cases grow slowly over about 10 years from polyps, which is why screening and polyp removal at colonoscopy prevent many cancers.
Colon and rectal cancers are closely related but treated somewhat differently. Colon cancer is usually operated on first. Rectal cancer sits in the narrow pelvis near the anal muscles, so radiotherapy and chemotherapy are often given before surgery, and preserving bowel control is a central concern.
Symptoms
- A lasting change in bowel habit, such as looser stools or new constipation, for more than 3 weeks
- Blood in or on the stool, or bleeding from the back passage
- A feeling of not emptying the rectum fully
- Tiredness and breathlessness from iron deficiency anaemia
- Unexplained weight loss
- Abdominal pain, bloating or a lump
- Sudden severe pain with vomiting and inability to pass wind, from a blockage
Causes and risk factors
Age is the main risk factor, though cases in people under 50 are increasing. Risk is raised by a diet high in red and processed meat and low in fibre, by excess weight, alcohol, smoking and inactivity, and by type 2 diabetes. Long-standing ulcerative colitis or Crohn's colitis increases risk. A parent, brother or sister with bowel cancer raises yours, and about 5 percent of cases result from inherited syndromes, mainly Lynch syndrome and familial adenomatous polyposis, which call for earlier and more frequent colonoscopy.
How it is diagnosed
- Stool test for hidden blood (FIT): Used for screening and to decide who needs a colonoscopy urgently.
- Colonoscopy with biopsy: Examines the whole bowel, removes polyps and takes samples from any tumour. It is the definitive test.
- CT of chest, abdomen and pelvis: Stages the cancer by looking at lymph nodes, liver and lungs. CT colonography is an alternative if colonoscopy is not possible.
- Pelvic MRI: Essential for rectal cancer. It shows how deeply the tumour extends and how close it lies to the surgical margin and sphincter.
- Blood and tumour tests: CEA as a baseline marker, and testing of the tumour for mismatch repair status, RAS and BRAF, which guide treatment and flag Lynch syndrome.
Treatment options
- Endoscopic removal: Polyps and some very early cancers can be removed completely during colonoscopy.
- Colon resection: Removal of the affected segment and its lymph nodes, usually by keyhole or robotic surgery, with the bowel joined again.
- Rectal cancer surgery: Total mesorectal excision, with a temporary stoma in many cases to protect the join. A permanent stoma is needed when the tumour involves the anal sphincter.
- Radiotherapy and chemotherapy before rectal surgery: Shrinks the tumour and lowers local recurrence. In some people with a complete response, a closely monitored watch-and-wait approach is discussed.
- Chemotherapy after surgery: Usually 3 to 6 months when lymph nodes are involved.
- Treatment of spread: Liver or lung surgery, ablation, chemotherapy, targeted drugs and immunotherapy for mismatch repair deficient tumours.
When it is urgent
Go to the nearest emergency department for severe abdominal pain with swelling, vomiting and no passage of stool or wind, which suggests obstruction, for heavy rectal bleeding with dizziness, or for sudden severe pain with a rigid abdomen. After bowel surgery, fever, worsening pain or a fast pulse may indicate a leaking join and need immediate assessment. Fever during chemotherapy is also an emergency.
Travelling to Türkiye for treatment
Rectal bleeding or a change in bowel habit should be investigated near home first. Travel works for a screening colonoscopy, a second opinion with review of pathology and MRI, or a planned resection, for which you should allow about 2 to 3 weeks before flying. Six months of chemotherapy, stoma care and 5 years of surveillance with scans and colonoscopy need local teams. If a temporary stoma is planned, agree in advance where and when it will be reversed.
Send your reports, scans and a short history and a Clinic-Y coordinator replies within 24 hours with suitable teams and written, all-inclusive proposals side by side. Reviewing your case is free.
Frequently Asked Questions
Will I need a stoma?
Most people with colon cancer do not. With rectal cancer a temporary stoma is common and is usually reversed after a few months. A permanent stoma is needed in a minority, mainly for very low tumours.
Is robotic surgery better?
Keyhole and robotic approaches give faster recovery than open surgery in suitable cases, with similar cancer results. The surgeon's experience matters more than the platform.
Should my family have colonoscopies?
First-degree relatives generally should start screening earlier than the general population. The exact timing depends on your age at diagnosis and tumour testing results.
Can rectal cancer be treated without surgery?
In selected people whose tumour disappears completely after chemoradiotherapy, careful surveillance is an option. It requires very frequent checks for several years and is not suitable for everyone.