What to expect from radiotherapy for bowel cancer

Radiotherapy uses planned radiation to treat a rectal or nearby bowel tumour and surrounding tissues. It may be given before surgery to help make an operation more manageable, after surgery, or alongside medicines, depending on the tumour and treatment plan. Your team uses scans to map the area and protect nearby bowel, bladder, and other organs as far as possible.

At each external treatment visit, you lie in the planned position while the machine delivers radiation. You do not feel the radiation, but effects can build during the course. Possible changes include looser or more frequent stools, urgency, rectal discomfort, urinary frequency or burning, skin irritation around the bottom, and tiredness. Tell the team before symptoms disrupt eating, sleep, or daily activities.

Follow instructions about bladder filling, bowel emptying, food, or medicines before planning and treatment visits. Keep a simple record of stool frequency, urgency, pain, urinary symptoms, and food tolerance. Drink according to your team's advice, choose nourishing foods you tolerate, and ask before making major diet changes. Wash the treated skin gently and avoid rubbing or unapproved creams.

Keep moving lightly when able, balance activity with rest, and arrange help with transport if fatigue makes driving difficult. Ask whether you should continue laxatives, anti-diarrhoea medicines, or supplements. Do not stop cancer treatment or prescribed medicines without speaking with your oncology team.

Contact your team promptly for repeated diarrhoea, blood in the stool, severe rectal pain, inability to pass urine, persistent vomiting, or dizziness with reduced urination. Fever, chills, or rapidly worsening abdominal pain require prompt assessment. Seek emergency help for heavy bleeding, severe abdominal pain with a swollen abdomen, collapse, or severe breathing difficulty.

Ask whether treatment is before or after surgery, whether chemotherapy is planned at the same time, and how to prepare your bladder and bowel. Ask which bowel or urinary changes need a same-day call, how to protect the skin, and whom to contact at night or on weekends.