Bowel Cancer
Inflammatory Bowel Disease
Irritable Bowel Syndrome
Exercise Induced Gastrointestinal Disturbance



1 in 20 people will develop bowel cancer during their lifetimes (more than 38,000 in the UK each year) making it the third commonest cancer and more than 16,000 people die from it every year (the second commonest cause of cancer death).  The key to improving survival is removal of pre-cancerous polyps (adenomas) and early diagnosis when cancer develops.  When diagnosed early, >90% of people are cured.  Unfortunately, only 9% of people with bowel cancer are currently diagnosed at this early stage. 
The most effective test for diagnosing bowel cancer or removing adenomas is called colonoscopy.   This involves taking medication to clear out the bowel before passing a special camera around the whole large bowel.  If adenomas are found, they can usually be removed during the test without the need for an operation and before they become cancerous.

Bowel cancer screening for people without symptoms has been introduced in many countries around the world to improve early diagnosis using a number of different methods.  The rationale behind screening is that polyps rarely cause symptoms and are often present for many years before they turn to cancer and there is also often a period after cancer develops before symptoms begin.  These facts provide an opportunity to prevent cancer or increase the chances of cure. 
In the UK, the first screening test introduced is called faecal occult blood testing (FOBt).  A stool sample is tested every 2 years from the age of 60-74.  Those people testing positive go on to have a colonoscopy.  The main advantages of FOBt are that it is not invasive, will detect most large cancers and reduces the risk of dying from bowel cancer by 17%.  The main disadvantages are that it misses approximately half of cancers and large numbers of adenomas.

There are also plans to introduce a test called flexible sigmoidoscopy (a camera test looking around the first part of the large bowel) in people aged 55 to diagnose cancers early and remove and adenomas.  This test reduces the risk of dying from bowel cancer by 43% and also reduces the risk of developing bowel cancer in the future by 33%.  The other main advantage of this test is that it only requires a more limited bowel cleansing with an enema and the camera does not need to be inserted so far into the bowel.  The main disadvantage is that only half of the large bowel is examined meaning that cancers in the far side may be missed.

In some parts of the world (USA and Germany), screening tends to be carried out with colonoscopy which has the benefits of flexible sigmoidoscopy but examines the entire bowel.  Colonoscopy is also useful for diagnosing other bowel conditions including inflammatory bowel disease (ulcerative colitis and Crohn’s disease) and for investigating people with changes in their bowel habit or bleeding.

Although the majority of people with a family history of bowel cancer do not have an increased risk, those with young or multiple relatives diagnosed with bowel cancer should undergo screening with colonoscopy.   If you have a family history of bowel cancer, you should see your GP to check whether this is necessary.
Some symptoms should prompt urgent investigation of the lower bowel.  These include rectal bleeding with a change in bowel habit to looser or more frequent stools in people over 40, rectal bleeding in people over 60, looser or more frequent stools in people over 60, anyone with a lump in the lower right side of the abdomen and men or non-menstruating women with anaemia. If your bowels have changed recently or you have noticed bleeding in your motions, you should see your GP to see whether you need further investigations.

Dr Cameron has extensive experience in colonoscopy and bowel cancer screening.  He is the Clinical lead for the Cambridge Bowel cancer screening centre and is one of only a handful of colonoscopists in the region accredited for bowel cancer screening.  He is also an assessor for the national bowel cancer screening programme in which he assesses the competence of colonoscopists who wish to take part in bowel cancer screening.  He is the Clinical lead for Endoscopy at Addenbrooke’s Hospital and provides a regional referral practice for the removal of larger adenomas.  He regularly teaches on the regional colonoscopy training courses in Norwich. 
Bowel cancer UK

 [back to top]



There are two main types of inflammatory bowel disease (IBD) – ulcerative colitis (UC) and Crohn’s disease.  They affect 1 in 250 people and are both caused by a combination of genetics (increasing numbers of genes have been discovered recently) and unidentified environmental triggers which means that there is a small increase in the risk of developing these conditions if you have a family member with either condition.  They most commonly occur in younger people (10-40) but can occur at any age.  It can sometimes be very difficult to tell which form of IBD a patient has. 
UC affects the rectum and spreads for a variable distance along the large bowel.  The typical symptoms are diarrhoea and bleeding.  Patients can also have abdominal pain and tiredness.  Crohn’s disease can affect any part of the gastrointestinal tract (from mouth to anus) but most commonly affects the small bowel and/ or large bowel.  The typical symptoms are abdominal pain, diarrhoea, tiredness and weight loss.  Both conditions can also affect the joints, skin or eyes. 
With both UC and Crohn’s disease, the severity of symptoms varies over time with “flare-ups” and periods of remission.
The principles of treatment are to control “flare-ups” and then to prevent them.  In most cases, treatment is with drugs.  For UC, these include 5-ASAs (such as mesalazine), steroids and immune suppressants (such as azathioprine).  For Crohn’s disease, the treatments are similar although there are new drugs called monoclonal antibodies (such as infliximab and adalimumab) and it can sometimes be treated with diet.  Stopping smoking is also a very important part of the treatment of Crohn’s disease.
Crohn’s and colitis UK

 [back to top]



Irritable bowel syndrome (IBS) is the name given to a collection of otherwise unexplained symptoms.  The most common symptoms are abdominal pain or spasms (often eased by going to the toilet), bloating or swelling of the abdomen and change in bowel habit (diarrhoea, constipation or alternation between both).  Patients may also get symptoms elsewhere in the body including headaches, dizziness, backache, urinary symptoms, tiredness, belching, nausea, anxiety or depression. 
The cause of IBS is not known but there are a number of possibilities.  These include food intolerances, alterations in normal gut bacteria and abnormal interactions between the gut and the nervous system.  People will often find that it is brought on or made worse by stress.
IBS is very common – about 1 in 6 people will have symptoms of IBS at any time and most people will experience them at some time.  It is more common in women and young people. 

There is currently no test for IBS.  The diagnosis is based on the presence of typical symptoms and exclusion of alternative conditions.  The number of tests required will depend on how likely alternative conditions (for example the presence of certain symptoms and the age of the patient).  These will always include a number of blood tests but may include colonoscopy or other tests.

A variety of treatments are used for IBS.  These include dietary modification, medication to relieve spasm in the bowel and low doses of drugs for depression which work on the abnormal interaction between the gut and the nervous system. 
The Gut Trust – national charity for irritable bowel syndrome

 [back to top]



can mean different things to different people.  These include pain or discomfort in the upper abdomen, feeling full or bloated, heartburn (burning rising up from the stomach into the chest caused by acid reflux), nausea or belching.  It is very common.  It may be caused by acid passing from the stomach into the oesophagus (gullet) which is known as gastro-oesophageal reflux disease (GORD), by ulcers in the stomach or duodenum, by medication particularly aspirin or anti-inflammatory pain killers (such as ibuprofen) or by infection with a bacteria called Helicobacter pylori.  This infection can be tested for by a number of methods including a stool test and at endoscopy.

Investigation with an endoscopy may be necessary, particularly in patients with persistent indigestion, new onset indigestion or if it is associated with vomiting, weight loss, problems with swallowing or in those passing black motions and is useful for excluding serious underlying causes of indigestion.  Most indigestion can be treated relatively simply with modifications in lifestyle (avoiding smoking, alcohol, coffee, chocolate or fatty food, losing weight, raising the head of your bed), medication including over the counter antacids or drugs that switch off stomach acid production (such as omeprazole) or treatment for Helicobacter pylori infection. 

Some patients should be investigated urgently including those with difficulty swallowing, unexplained pain in the upper abdomen and weight loss (with or without back pain), a lump in the upper abdomen without indigestion, those aged 55 years and older with unexplained and persistent indigestion that started recently or those of any age with  indigestion and any of gastrointestinal bleeding, difficulty in swallowing, unexplained weight loss, persistent vomiting, anaemia, a lump in the upper abdomen.

 [back to top]



This occurs most frequently in runners and is more commonly known as “runner’s trots”.  Approximately a third of runners experience some form of gastrointestinal upset during or after exercise.  Symptoms vary from abdominal cramps and nausea to flatulence and diarrhoea.  These symptoms can be very severe on occasions and cause major disruption to training and racing.  Dealing with these symptoms involves excluding underlying medical conditions, a variety of dietary adjustments and occasionally medication.  As a keen long distance runner with several marathons, half marathons and 10Ks under his belt, Dr Cameron has been able to help many people with this problem over the years.

 [back to top]