Rectal Cancer

Rectal cancer is a cancer that begins in the rectum and may cause bleeding or a change in bowel habits.

The rectum is the lower part of the large bowel, where stool is stored before it leaves the body. The tumour’s position, size, and whether it has reached nearby tissues guide the care plan.

Blood in stool is a very common presentation of rectal cancer, and a change in bowel habits is also a very common presentation. Changes may include looser or harder stools, needing to go more often, or a feeling that the bowel has not emptied.

Other possible signs include narrow stools, mucus, abdominal discomfort, tiredness, or unplanned weight loss. These symptoms also occur with non-cancerous conditions, so assessment is needed rather than self-diagnosis.

Rectal cancer develops when cells in the rectal lining acquire changes that make them multiply and survive in an uncontrolled way. A growth may begin as a polyp and, over time, become cancerous, although not every polyp does so.

There is usually no single cause that can be identified for one person. A specialist considers personal history, inherited susceptibility, and bowel health when discussing risk.

Clinicians describe rectal cancer by how deeply it has grown and whether it involves lymph nodes or other organs. Imaging and tissue results help establish this stage.

Some treatment is given before surgery to shrink or control the tumour. After treatment, the team reviews the response and plans surveillance around examinations, scans, and bowel symptoms.

Risk can be higher with increasing age, a close family history of bowel cancer, inherited bowel-cancer syndromes, or long-standing inflammatory bowel disease. Previous bowel polyps and some lifestyle patterns may also contribute.

Having a risk factor does not mean cancer will develop, and rectal cancer can occur without an obvious risk factor. Tell the clinician about relatives with bowel cancer and any previous bowel investigations.

Assessment may include a rectal examination, blood tests, and colonoscopy. During colonoscopy, a clinician views the bowel and can remove a polyp or take a biopsy for laboratory examination.

Scans such as magnetic resonance imaging or computed tomography show the tumour’s location and help check nearby structures. The results are combined to select treatment and explain what to expect.

Treatment depends on the tumour’s stage, position, biology, and your general health. Chemotherapy before surgery and radiotherapy may be used to reduce the tumour or lower the chance of it returning in the treated area.

Rectal cancer surgery removes the tumour with a margin of healthy tissue. Some people need stoma surgery, which creates an opening on the abdomen for stool to leave into a pouch; it may be temporary or long-term. Your team will explain the planned operation and bowel changes.

Bowel habits can change after treatment. Keep a record of urgency, frequency, stool consistency, pain, bleeding, and foods that seem to worsen symptoms. A dietitian or specialist nurse can help with hydration, nutrition, and adapting meals.

The tumour can narrow the bowel and make stool difficult to pass. Bleeding may contribute to anaemia, while treatment can affect bowel control, bladder function, sexual function, or energy. New or worsening pain, vomiting, a swollen abdomen, or inability to pass stool or gas needs urgent medical advice.

Some risk cannot be changed, but not smoking, staying physically active, eating a varied diet, and limiting processed meat may support bowel health. Screening and review of persistent bowel changes can find polyps or cancer earlier.

Look for a colorectal or gastrointestinal oncology team that can coordinate endoscopy, imaging, surgery, radiotherapy, systemic treatment, nutrition, and stoma support. Bring a list of medicines, symptoms, previous tests, and family history to the appointment.