Radiation Therapy for Bowel Cancer

Radiation therapy uses targeted radiation to damage cancer cells. In bowel cancer care, it is more commonly used for rectal cancer than colon cancer, but it may also be used in selected situations to help control symptoms or treat cancer in a specific area.

This article is for general information only. Your radiation oncologist or healthcare team can explain whether radiation therapy is suitable for your situation.

When Radiation Therapy May Be Used

Radiation therapy may be used before surgery, after surgery, together with chemotherapy or as part of palliative care. The reason for using it depends on the cancer location, stage, symptoms and treatment plan.

For a broader overview, read our Treatment for Early Bowel Cancer and Treatment for Advanced Bowel Cancer articles.

Radiation Therapy for Rectal Cancer

Radiation therapy is often discussed in rectal cancer because the rectum is located in the pelvis and treatment can help shrink the tumour before surgery or reduce the risk of cancer returning in the area.

Sometimes chemotherapy is given at the same time. This is called chemoradiation or chemoradiotherapy.

Palliative Radiation Therapy

If bowel cancer is advanced, radiation therapy may be used to help relieve symptoms such as pain, bleeding or pressure from a tumour. In this situation, the goal may be comfort and symptom control rather than cure.

You can learn more in our Palliative Treatment for Bowel Cancer article.

Possible Side Effects

Side effects depend on the area treated and the dose. Possible side effects may include tiredness, skin irritation, diarrhoea, bowel changes, bladder irritation, nausea or changes in sexual function.

Your healthcare team should explain which side effects are more likely in your case and what to do if they happen.

Preparing for Radiation Therapy

Before treatment begins, you may have planning scans and measurements to help target the radiation accurately. The treatment team will explain the schedule, preparation steps and what to expect during each session.

Ask who to contact if side effects become difficult between appointments.

Questions to Ask

• Why is radiation therapy recommended for me?
• What is the goal of treatment?
• How many sessions will I need?
• Will I also need chemotherapy?
• What side effects should I expect?
• Which symptoms need urgent medical advice?

Final Thoughts

Radiation therapy for bowel cancer may be used for treatment or symptom control depending on the situation. Ask your radiation team to explain the goal, expected benefits, possible side effects and follow-up plan.

For appointment preparation, visit our Bowel Cancer Questions to Ask Your Doctor guide.