What to expect from radiotherapy for rectal cancer

Before treatment, scans define the rectum, nearby bowel, bladder and other tissues. You may be asked to keep a particular bladder or bowel state so the position is similar at each visit. External radiation is delivered while you lie still; the session itself is brief, but appointments include positioning and checks.

Radiotherapy may be given before surgery or with medicine that makes cancer cells more sensitive to radiation. Loose stools, urgency, rectal discomfort, bladder irritation, skin soreness and tiredness can develop. Your clinicians can adjust supportive care and will check nutrition, hydration and blood results when needed.

Use the preparation instructions supplied by your team and keep a simple record of stool frequency, urgency, pain, urine changes and food or drink intake. Choose gentle foods if your clinicians recommend them, replace fluids when stools are loose, and protect irritated skin with only products approved by the radiation team. Keep appointments and tell staff about previous pelvic treatment or inflammatory bowel disease.

Contact the treatment team promptly for frequent watery stools, blood in the stool, severe rectal or abdominal pain, inability to keep fluids down, fever, dizziness or very little urine. Seek emergency care for fainting, confusion, uncontrolled bleeding or severe breathing difficulty. Do not wait for the next appointment when symptoms are rapidly worsening.

Ask how radiotherapy fits with chemotherapy and surgery, what bladder and bowel preparation you need, and which foods or medicines may ease bowel changes. Ask how skin care should be handled, whether work or travel needs adjusting, and who to call at night or during a public holiday.