Bowel Cancer Q&A

Ask the Consultant

Five of our leading bowel cancer specialists answer common questions on bowel cancer including signs and symptoms, risk factors as well as screening and treatments. Learn more in our free bowel cancer guide.

Dr Timothy Leigh

Bowel cancer refers to a cancerous growth which is normally found in the large bowel also known as the colon, and is the commonest type of bowel cancer. t is also possible to have tumours in the small bowel but these are much less common although still technically bowel cancers.


Mr Mohammed Saeed

Bowel cancer is a term used to describe cancer of the large bowel and is further divided into colon and rectal cancer. Rectal cancer occurs in the part of the large bowel called the rectum which is the first 15cm from the back passage. This cancer is usually slow growing and is the second most common cancer with about 40 000 people diagnosed each year in this country.


Mr Simon Radley

Bowel cancer is the term used to describe a cancer growing in the large bowel which is also known as the large intestine. Depending upon where the cancer develops it may also be called colonic cancer or rectal cancer. About 1/3 of bowel cancers develop in the last part of the large intestine the rectum These are called termed rectal cancers and cancers developing elsewhere in the large bowel are all known as colonic cancers.


Mr James McCourtney

Bowel cancer is one of the most common types of cancer in the United Kingdom. Also known as "colorectal cancer" it is cancer of the large bowel (the colon and rectum). Every year around 40,000 new cases are diagnosed in the United Kingdom and sadly about 16,000 people will die from this condition. One in 20 of us over 50 will get bowel cancer at some stage in our lives.


Lee Dvorkin

Bowel cancer, also known as colorectal cancer, is a cancer situated anywhere in the large bowel (the colon or rectum). Bowel cancer is the 4th most common cancer in the UK and the second most common cause of cancer death with over 41,000 new cases diagnosed each year1. Bowel cancer is most common in the over 60's and is rare in people younger than 40 years old. The majority of cases develop from pre-cancerous polyps (tiny growths in the bowel), which if left untreated can, over years, develop into cancer.

1 Cancer Research UK: Bowel cancer statistics. http://www.cancerresearchuk.org/cancer-info/cancerstats/types/bowel

Dr Timothy Leigh

Many people have no symptoms from their bowel cancers but those who develop symptoms may complain of a change in their bowel habit, overt bleeding from the lower bowel with blood in the stool or toilet. Other symptoms may include abdominal pain or bloating and unexplained weight loss. Blood tests may also reveal an unexplained anaemia which can indicate a loss of blood from bleeding within the bowel.


Mr Mohammed Saeed

Common symptoms include:

  • Rectal bleeding particularly blood mixed with stool change in bowel habit particularly more frequent looser stools
  • Feeling of incomplete bowel evacuation
  • Abdominal pains and bloating after eating
  • Unexplained anaemia
  • Presence of an abdominal lump

Mr Simon Radley

The common symptoms of bowel cancer can  include blood in the stools, a change in bowel habit- usually to looser and more frequent and abdominal or tummy pain. These symptoms are very common and most people with them will not have bowel cancer. For example, piles or hemorrhoids can cause bleeding and irritable bowel syndrome may cause tummy pains and change in bowel habit. Nevertheless, if you develop any of these symptoms you should always seek medical advice. Other less common symptoms may include weight loss, anaemia and a feeling of incomplete bowel emptying. The development of any of those symptoms should be a prompt to seek medical advice.


Mr James McCourtney

The symptoms of bowel cancer can include:

  • bleeding from the back passage or blood in your bowel motions (stools)
  • a change in bowel habit for more than 4-6 weeks with diarrhoea or looser stools
  • pain in your abdomen or back passage
  • a low blood count (anaemia)
  • a lump that your GP can feel in your abdomen or back passage
  • a sensation that you need to strain in your back passage as if you need to go to the toilet
  • weight loss.

In some situations bowel cancer can cause a blockage in the bowel (obstruction). When this happens symptoms including severe cramping abdominal pain; bloating; constipation; and vomiting.


Lee Dvorkin

The symptoms of bowel cancer are variable and can include:

  • Diarrhoea or loose poo for over 3 weeks
  • Blood in the poo
  • Losing weight unintentionally
  • Some cancers can bleed and cause anaemia which may lead to tiredness and weakness
  • Sometimes cancer can block the bowel. If this happens symptoms include: cramps, vomiting and bloating

If you are suffering from any of these symptoms you should see a bowel specialist for investigation

Dr Timothy Leigh

Everyone is potentially at risk, but as with most cancers, the risk increases with age particularly over 60 years of age. Other factors which increase the risk are a family history of first degree relatives who have developed bowel cancer, particularly if there have been several members and if they have developed it at an early age, say under 50 years old.


Mr Mohammed Saeed

Age - Around 9 out of 10 patients diagnosed with bowel cancer are  aged 60 or over. Therefore age is a risk factor. Diet - A diet rich in red and processed meat and low fibre is considered a risk factor.  Weight - Bowel cancer is more common in overweight and obese people Exercise - Sedentary lifestyle is a risk factor. Alcohol and smoking – High alcohol intake and smoking increase the risk of developing bowel cancer. Family history - A close relative such as mother, father, brother or sister developing bowel cancer below the age of 50 years will put you at increased risk of bowel cancer. Personal history of ulcerative colitis and crohns disease predisposes to an increased risk of developing bowel cancer.


Mr Simon Radley

Bowel cancer is one of the most common types of cancer with around 40,000 people being diagnosed in the UK each year. It affects roughly the same number of men and women. Whilst bowel cancer can affect people of any age 9 out of 10 cases occur in people over 60 years of age. There is an increased risk of bowel cancer developing in patients with longstanding conditions such as Ulcerative Colitis or colonic Crohn’s disease. There are certain rare genetic conditions such as Familial Adenomatous Polyposis (FAP) which can lead to bowel cancers. We are also aware of other more common genetic predispositions such as the Lynch Syndrome or Hereditary Non-Polyposis Colon Cancer (HNPCC) which are associated with a greater risk of developing bowel cancers in some families.


Mr James McCourtney

A number of factors are thought to increase your risk of developing bowel cancer. These include:

  • Age almost 9 in 10 cases occur in people over the age of 60
  • Diet your risk is increased if you have a diet high in red or processed meats and low in fibre
  • Weight overweight or obese people are more at risk of getting bowel cancer
  • Exercise inactivity increases your risk
  • Alcohol and smoking excessive alcohol consumption and smoking increase your risk
  • Family history if you have a close family member (mother, father, brother, sister) who developed bowel cancer under the age of 50 then this increases your lifetime risk
  • Ulcerative colitis and Crohn's disease these bowel conditions can increase an individual's risk of bowel cancer if they have had the condition over a long period of time.

Lee Dvorkin

The biggest single risk factor is age. More than 8 out of 10 bowel cancers are diagnosed in people aged 60 or over. So the risk increases as you get older.

Other factors thought to increase the risk include smoking, obesity and eating excessive red meat, alcohol, animal fat and sugar. A reduced risk has been noted in those who exercise and eat more fibre and pulses

There are some other medical conditions that increase the risk of bowel cancer and these include; Ulcerative colitis, Crohns Disease and having lots of polyps (which are more common as you get older).

Dr Timothy Leigh

Bowel cancer is believed to arise from polyps which can occur on the inner surface of the bowel wall. If there is a family history of bowel cancer, the safest precaution is to undergo a colonoscopy procedure to look for, and remove, polyps in the bowel as they are known to be a potential precursor to the development of bowel cancer. It is normally recommended that this procedure is performed at an age of 8 years earlier than when the youngest family member developed their bowel cancer. If polyps are found and removed, it is usual for that person to have further surveillance procedures at intervals in the future to ensure that any further polyps can be removed before they can turn into cancers.


Mr Mohammed Saeed

Individuals with family history of bowel cancer should have a high fibre and low red and processed meat diet. They should have a low alcohol intake, not smoke, exercise regularly and avoid becoming overweight. They should speak to their doctor regarding screening for bowel cancer and in those with very high risk may need genetics testing to fully define their risk and be referred to a specialist for screening and in a small number of cases  (familial adenomatous polyposis) may need preventative surgery


Mr Simon Radley

Yes, we increasingly recognize the importance of family history in determining the risk of developing bowel cancer. All cancers are a disease affecting genes. The mutated gene or genes allow a cancer to develop. We currently describe most cancers as being sporadic i.e. we think that the gene mutation is in some way acquired during your lifetime. This could be due to an environmental trigger such as a diet which includes red meat and excess fat, an excess of alcohol, smoking, lack of exercise and obesity. In other situations we recognize the importance of family history and in about 1 in 10 patients we can identify an inherited genetic basis. We recommend that where an individual has a history of bowel cancer in the family they seek specialist medical advice.


Mr James McCourtney

Yes. Speak to your GP who will establish if you fall into a higher risk group (several family members from the same side of the family affected by bowel cancer). If this is the case then you will be referred to a clinical genetics specialist. After a detailed interview and blood tests if you are felt to have a higher than average risk of bowel cancer then you will be referred to a bowel specialist. They will discuss with you the need for having regular screening tests (colonoscopy) to detect any signs of bowel cancer as early as possible.

If you do not fall into a high risk category but have a family history of bowel cancer then you should report the development of any suspicious symptoms of bowel cancer to your GP; and take part in the national bowel cancer screening programme once you become eligible.


Lee Dvorkin

Bowel cancer is very common so having a relative with bowel cancer is not unusual. The chance of getting bowel cancer goes up only if the family history is very strong. A strong family history means having several relatives with bowel cancer, especially if they are particularly young.

Examples of a strong family history might be; having a first degree relative diagnosed before the age of 45 or having two first degree relatives diagnosed at any age. To have a strong family history, the affected relatives must all come from the same side of the family.

If you have a strong family history of bowel cancer you may need to be referred to a genetics service. You will need to see a bowel specialist for regular colonoscopies to pick up any signs of cancer as early as possible.

Dr Timothy Leigh

Bowel cancer can be detected in several ways, although the diagnosis ultimately depends on obtaining a tissue specimen of the tumour, usually at colonoscopy, which can be examined and diagnosed under a microscope. Colonoscopy therefore is the commonest methods of making the diagnosis although other tests such as a CT scan, CT colonography, ultrasound scanning, as well as a barium enema examination will also give results which may indicate a strong likelihood of underlying bowel cancer.


Mr Mohammed Saeed

Bowel cancer is detected by a camera examination called a colonoscopy. This is a fibreoptic camera about the width of a finger and a metre long which is introduced through the back passage under sedation. The camera has a channel through which a biopsy can be taken. Alternatively a special body scan called a virtual colonoscopy can be performed to detect abnormality within the bowel but it lacks the ability to obtain a biopsy.


Mr Simon Radley

Bowel cancer can be detected in patients without symptoms by screening. In England now there are two types of screening test available. The first is a short telescope test known as a flexible sigmoidoscopy which is offered to everyone at the age of 55. The second type of screening test aims to detect blood in the stools. This type of testing begins at the age of 60 and is repeated every 2 years until the age of 74. If a result comes back positive a colonoscopy or complete examination of the large bowel will be recommended. Screening allows for early detection or even prevention of bowel cancer and improves the chances of a complete cure. 


Mr James McCourtney

If you have any of the symptoms of bowel cancer the first step is to see your GP who will ask you specific questions, examine your abdomen and may examine your back passage (rectal examination). Blood tests might also be checked to see if you have a low blood count (anaemia). The GP may then refer you to hospital to see a bowel cancer specialist. On the basis of your clinic assessment a camera test under sedation (colonoscopy) may be arranged to examine the full length of the bowel; or x-ray tests (barium enema x-ray; or a virtual colonoscopy-CT colonography). After bowel cancer tests have been completed you will be asked to return to the hospital for the results at an early stage.

If you have no symptoms but have reached a certain age (in Scotland 50; in England 60) you will be offered bowel cancer screening every two years. This is carried out by taking a small sample of stool and testing it for invisible traces of blood. Screening plays an important part in the fight against bowel cancer as it can help detect the cancer before it causes obvious symptoms and increases your chances of surviving this condition.


Lee Dvorkin

Usually patients develop symptoms and go to see their GP. The GP will do a rectal examination and some blood tests and then send the patient to see a specialist in the hospital. The two most common investigations to diagnose bowel cancer is a colonoscopy (a camera examination of the large bowel) and a CT colonogram (instead of having the camera put inside your bowel, the doctor looks at x ray pictures of the bowel).

Some patients without symptoms are diagnosed through the NHS

Bowel Cancer Screening Programme. Screening is offered to everyone aged 60 to 69 years old (75 years in some areas). Every 2 years patients are asked to send a poo sample to the laboratory. If blood is detected in the poo a colonoscopy is offered to see if there are early signs of cancer.

Dr Timothy Leigh

There are various treatments available depending on the tumour and how advanced it is at the time of diagnosis. A tumour which is shown to be restricted entirely to the bowel wall can be treated with surgery alone, but if there is a suggestion that the tumour may have spread either through the bowel wall or to local lymph nodes or possibly further away such as the liver or lungs then treatment may be in the form of chemotherapy, possibly in combination with surgery. Occasionally it is possible to remove surgically single areas where the tumour has spread in the liver (metastases) and there are also other more specialised techniques available to treat such metastases.


Mr Mohammed Saeed

The primary treatment for bowel cancer is surgical removal of the segment of bowel containing the cancer. This can be done either by open surgery with a cut in the tummy or in some cases with keyhole surgery where the cut in the tummy is much smaller and therefore recovery is much faster. Chemotherapy and for rectal cancer radiotherapy are used in addition to rather than instead of surgery depending on the extent of the cancer.


Mr Simon Radley

There are an increasing number of treatments available for bowel cancer. The main treatments have tended to be surgical and usually involve removing a section of the affected bowel. This can frequently be performed as a key hole (laparoscopic or robotic) procedure with excellent results for patients in terms of recovery, scarring etc. Radiotherapy is frequently used for cancers in the rectum, to shrink cancers or reduce the risk of them recurring. An increasingly large variety of chemotherapies are available to use to prevent the risk of recurrence after surgery or to treat patients who have recurrent or more advanced disease when they are diagnosed. 


Mr James McCourtney

Surgery is the main treatment in 8 out of 10 people with bowel cancer. Chemotherapy or radiotherapy may also be used as well as an operation.

Most people with early bowel cancer have surgery to remove all of the cancer. If the cancer has spread into the glands next to the bowel (lymph nodes) then there is a chance that the cancer cells may have spread to other parts of the body such as the liver and lungs. These cells can develop into secondary cancers (metastases) in the future so additional treatment may be needed.

Radiotherapy tends not to be used to treat cancer of the large bowel (colon) but is frequently used before or after surgery if you have a cancer in the back passage (rectum). Radiotherapy can be combined with chemotherapy to shrink the cancer and make it possible to completely remove it.

Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. The drugs disrupt the cancer cells growth and circulate in the bloodstream throughout your body. Some chemotherapy is given prior to surgery for rectal cancer along with radiotherapy. This aims to shrink the cancer and make it easier to remove. Chemotherapy may also be given after surgery for bowel cancer. You may also be given chemotherapy if your bowel cancer has spread.

Biological therapies are newer drugs that can help the body to control the growth of cancer cells.


Lee Dvorkin

The treatment depends on how advanced the cancer is when it is diagnosed. The mainstay of treatment for confirmed bowel cancer is an operation to remove the cancer and its surrounding lymph glands. The bowel ends are usually joined back together but sometimes a colostomy bag is required. Nowadays, these operations are performed by keyhole surgery and patients typically spend less than a week in hospital.

Often, surgery is all the treatment that is needed but If the cancer is advanced chemotherapy is offered and this can last for 6 months. Surgery can also be used to remove certain cancers that have spread to the liver or lungs but this is not always possible.

For cancer in the rectum, radiotherapy is often used to shrink down the tumour before surgery

Dr Timothy Leigh

I have been a Consultant Gastroenterologist for almost 20 years, and I have a special interest in performing colonoscopy and the treatment of bowel diseases.


Mr Mohammed Saeed

I have been a consultant colorectal surgeon for the past 16 years and have treated hundreds of patients with this condition. Early detection through screening and increased awareness of lifestyle choices is important. As a surgeon my greatest pleasure is being able to us my surgical skills to help cure people of this cancer.    


Mr Simon Radley

I became a consultant colorectal surgeon at the Queen Elizabeth Hospital Birmingham in February 1998. I had received specialist training in colorectal surgery at the world famous St Marks Hospital in London. I also completed a travelling fellowship to the United States visiting Boston, Minneapolis and the Mayo Clinic. As a consultant I have been the Clinical Lead for General Surgery and I am the Lead Clinician for Colorectal Cancer in the trust. I’m a former council member of the Association of Coloproctology of Great Britain and Ireland. I have and continue to publish extensively in scientific journals. I have been responsible for the development of laparoscopic and robotic surgery within the trust as well as novel techniques for the treatment of haemorrhoids and faecal incontinence. 


Mr James McCourtney

I was fortunate to work with some exceptional surgeons both in Glasgow and London but my time spent as Resident Surgical Officer at St Mark's Hospital in London in 1999, at the end of my training, was undoubtedly the shining highlight. St Mark's is a world famous hospital for the treatment of bowel cancer as well as other colorectal conditions. I was privileged to be trained there by “giants” in the fields of colorectal surgery and colonoscopy.

After taking up post as a consultant colorectal surgeon in 1999 I made the decision to leave the NHS to work in full-time private practice at Ross Hall Hospital in Glasgow in December 2007. This was the second major highlight of my career to date. I am extremely lucky to be part of an excellent team of doctors and nurses providing colorectal surgery services with continuity of care to patients from Scotland and beyond.


Lee Dvorkin

I was appointed as a Consultant General & Colorectal Surgeon in 2011 to a large teaching Hospital in London. My clinical practice encompasses all aspects of General & Bowel surgery with a special interest in colorectal cancer, colonoscopy and inflammatory bowel disease.

I am considered a regional expert in laparoscopic (keyhole) surgery and have been appointed by The Royal College of Surgeons as a Director of one of their National Fellowship Training Programmes in order to teach keyhole surgery to other doctors.

I am currently Clinical Lead for General Surgery and Training Programme Director for junior doctors in my hospital. I was appointed as a Senior Lecturer at UCL Hospital in London and enjoy teaching.

My hobbies include cycling and outdoor pursuits.

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