The evidence base for the symptom checker

Provenance of the ‘symptom checker’ 

This is the first professionally validated website advising the general public on the management of bowel symptoms. The Association of Coloproctology of Great Britain and Ireland (ACPGBI) has over 1000 surgeons, nurses, and allied professional members who diagnose and look after the majority of people with mild and serious bowel conditions in the UK. Two important aims of the ACPGBI are:


·      to provide and disseminate information and advice to health professionals and members of the public on matters relating to diseases of the large bowel


·      to promote the most efficient and effective use of healthcare resources


The need for a ‘symptom checker’

The Internet based ‘symptom checker’ is designed for patients with mild to moderate symptoms who are unsure whether they need to see their general practitioner.

Patients with severe symptoms that prevent them working, eating or sleeping require advice regardless of the nature of their symptoms and these patients clearly need to see their GP. 

The three key symptoms of most bowel disorders are: 

  • rectal bleeding
  • a change in bowel habit
  • abdominal pain

These are ver
common in the general population [1,2], over 7 million people have rectal bleeding in the UK each year, 99.9% of who do not have a serious bowel condition! Similar numbers of patients have a change in their bowel habit and abdominal pain and it would be a great burden on primary care services if they all decided to see their GP. Research suggests that the majority of people currently manage their symptoms quite appropriately in the community without medical advice. However increasing awareness of the occasional serious significance of these symptoms means that people in the community will increasingly need reliable information to help them decide when they should see their GP. 

It is also well known that 10% of patients with bowel cancer have a delay in diagnosis of over a year and 30% of over 6 months. In a significant number of patients the long delays are because people are unaware of the significance of their symptoms [9]. These delays have not been reduced by previous public awareness campaigns over the last 60 years [9] and new methods such as this 'bowel symptom checker' need to be tried if any reduction in the delay is to be achieved in the future

As symptoms in most patients are self-limiting and are caused by benign conditions, it is both appropriate as well as safe for them to self-care in the community. The question is - can an internet based symptom checker help the majority of people with benign disease avoid investigation while not greatly delaying diagnosis of serious disease.

The symptom checker should therefore be able to:

1. Identify the majority of patients at higher risk of having serious bowel disease.

2. Identify those patients at very low risk.

3. Outline the likely cause of the symptoms.

4. Advise on simple dietary and pharmacological treatments.

5. Provide all patients seeing their GP with a printed record of their symptoms.

5. Not excessively delay the diagnosis of cancer. 

Essential requirements to develop a Symptom Checker 

It is necessary to be able to stratify a patient’s risk of having a serious bowel condition on the basis of the patient’s symptoms, age and length of history and establish 'treat watch and wait' diagnostic strategies are safe. 

Risk stratification. 

This is based on studies of the nature of rectal bleeding and a change in bowel habit[1] in the community and the  symptoms of bowel cancer [3,4] . These estimates are in keeping with numerous peer reviewed studies [2-7] and published abstracts over 18 years [10-20] on subsets of 31,000 patients seen in Portsmouth out patient clinics over 25 years and studies from other centres.

Short delays in diagnosis of bowel cancer do no harm

A large review suggested that the theoretical basis for the benefit of earlier diagnosis after the onset of symptoms was weak and this was supported by the majority of observational studies.These findings are supported by the fact that many bowel cancers have long natural histories, which means many may have been present for at least 2 years before they develop symptoms, long enough for most of the aggressive cancers, which cause the majority of deaths from bowel cancer to have disseminated and become incurable. In contrast those cancers that are still curable after this length of time are unlikely to become incurable immediately after the onset of symptoms. This suggests that ‘treat watch and wait’ diagnostic strategies including ‘delays’ of up to 6-8 weeks, which help the majority of patients with transient symptoms from benign disease avoid investigation will not reduce the chance of cure of cancer patients.

Advice on the management of the patient’s symptoms

This is based on one consultant surgeon’s clinical experience (MRT; see CV) of working in specialized colorectal clinics in Portsmouth over 27 years. Over this period of time MRT has seen almost 12,000 patients with bowel problems most of who have had a flexible sigmoidoscopy and around 600 had bowel cancer. Advice to patients on the management of their symptoms has evolved over the last 20 years through working with Lynn Faulds Wood on public awareness campaigns.

Peer Reviewed articles published in journals

1. Thompson JA, Pond CL, Ellis BG, Beach A, Thompson MR. Rectal Bleeding in General and Hospital Practice; 'The tip of the iceberg'.  Colorect Dis 2000; 2: 288-293

2. Thompson MR, Heath I, Ellis BG, Swarbrick ET, Faulds Wood L, Atkin WS.  Identifying and managing patients at low risk of bowel cancer in General Practice.  BMJ 2003; 327: 263-265

3. National Referral Guidelines for Bowel Cancer  Colorectal Dis 2002; 4 (4): 287-297

4.  Flashman K, O’Leary DP, Senapati A, Thompson MR. The Department of Health’s ‘two-week standard’ for bowel cancer: is it working?  Gut 2004; 53(3): 387-391

5.  Ellis BG, Thompson MR. Factors identifying higher risk bleeding in general practice.  Br J Gen Pract 2005; 55(521): 949-55

6.  Thompson MR, Perera R, Senapati A, Dodds S. The diagnostic and predictive value of the common symptom combinations of bowel cancer. BJS 2007: 94: 1260-1265

7.  Thompson MR, Flashman KG, Wooldrage K, Statistician, Rogers PA, Senapati A, O’LearyDP, Atkin WS. Flexible sigmoidoscopy and whole colonic imaging in the diagnosis of cancer in patients with colorectal symptoms.  Br J Surg 2008; 95: 1140-114

8.Thompson MR,  Asiimwe A,  Flashman K,  Tsavellas G Is earlier referral and investigation of bowel cancer patients presenting with rectal bleeding associated with better survival?   Colorectal  Disease 2011;13:1242-1248  

9. Thompson MR, I. Heath, E. T. Swarbrick, L. Faulds Wood and B. G. Ellis Earlier diagnosis and treatment of symptomatic bowel cancer: can it be  achieved and how much will it improve survival?  Colorectal Disease 2011; 13, 6–17

Published Abstracts and Posters presented to National and International Meetings

 10. Dodds SR, Thompson MR. The significance of rectal bleeding in symptomatic colorectal disease Poster.  Tripartite Meeting.  Sydney, Australia. 1993 

 11.Vakis SA , Dodds SR, Thompson MR.  Presentation of colorectal cancer at a Surgical Out-Patients.  How occult a sign is rectal bleeding?  Int.J.Colorect.Dis. 1995; 10:240

 12. Thompson MR, Armstrong-James D, Moss S, Prytherch D. Prevalence of colorectal      cancer in patients presenting with anorectal bleeding.  Effect of age and dark red bleeding. Gut 1996; 39 (Supple.1), F181.

 13. Dodds S, Dodds A, Vakis S, Flashman K, Senapati A, Cripps NPJ, Thompson MR. The value of various factors associated with rectal bleeding in the diagnosis of rectal cancer. Gut 1999; 44 (Supple 1): Th396.

 14. Nichols PH, Dodds S, Dodds A, Flashman K, Senapati A, Cripps NPJ, Thompson MR. Painless rectal bleeding or bleeding without pile symptoms. Colorect Dis. 1999; 1(Supple1) 23

15. Chave H, Flashman K, Cripps NPJ, Senapati A, Thompson MR. The Relative Values of the Characteristics of Rectal Bleeding in the Diagnosis of Colorectal Cancer. Colorect Dis 2000; 2 (Supple 1): 1/01

16. Branagan G, Senapati A, Thompson MR, O’Leary DP.  Dark vs bright red bleeding in the diagnosis of colorectal cancer.  Colorect Dis 2004; 6 (Suppl 1): 47

17. Ellis, B, Baig MK, Cripps NPJ, Senapati A, Flashman K, Jaral M, Thompson MR. Common modes of presentation of colorectal cancer patients Colorect Dis 1999; 1 (Supple 1): 24/P26

18. Dodds S, Dodds A, Vakis S, Flashman K, Senapati A, Cripps NPJ, Thompson MR.  Effect of age and sex on value of symptoms in diagnosis of colorectal cancer.  Gut 1999; 44(Suppl 1): A15/T60.

19. Chave H, Flashman K, Senapati A, Cripps NPJ, Thompson MR. Characteristics of the change in Bowel Habit in Patients with Colorectal Cancer. Colorect Dis 2000; 2 (Supple 1): 1/0ral 2

20. Baig MK, Whatley P, Thompson MR. Delay in diagnosis and treatment of colorectal cancer; Does it affect outcome? Gut 1999; 44(Suppl.): A143. (Abstract TH572)

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