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Br J Gen Pract. 2005 January 1; 55(510): 14–19.
PMCID: PMC1266237

Diagnostic work-up of rectal bleeding in general practice

Christoph Heintze, MD, Lecturer in Primary Care and Research Fellow
Dorothea Matysiak-Klose, MD, Research Fellow
Thorsten Kröhn, MD, General Practitioner
Ute Wolf, MD, Research Fellow
Alexander Brand, Predoctoral Fellow
Christoph Meisner, Research Associate and Imma Fischer, PhD, Research Associate
Hartwig Wehrmeyer, Documentation Officer and Vittoria Braun, MD, Professor and Senior Lecturer in Primary Care



GPs have many patients with gastrointestinal discomfort. Among bowel-related complaints, the sign of rectal bleeding is of particular importance in patients aged 50 years and above, as it can be an early sign for serious bowel diseases such as colon carcinoma. Despite many guidelines offered to GPs for screening and early detection of colorectal carcinomas, there is very little information about the actual diagnostic approach to the sign of rectal bleeding.


The aim of the study was to collect data concerning treatment strategies used by GPs who treat patients presenting with rectal bleeding.

Design of study

Prospective data collection.


General practices in Germany.


Over the course of a year, GPs recorded their treatment strategies in patients presenting with rectal bleeding and associated symptoms. Using a digital practice patient file, physicians participating in the study were able to continuously transmit data electronically to the researchers of the study about diagnostics, referrals, hospital admissions, and final diagnoses.


During the course of 1 year, 94 participating physicians collected data on 1584 patients. Information about treating rectal bleeding was recorded for 422 patients; 60% of the patients were referred to specialists in internal medicine or gastroenterologists for further diagnostics. A colonoscopy was the most frequently performed diagnostic procedure (46.2%). Twenty-two per cent (n = 93) of the patients — 54 of them aged 50 years and above — were exclusively treated by their GP without conducting a colonoscopy or cooperating with specialists. For these patients, GPs diagnosed less severe diseases like haemorrhoids or other proctologic diseases.


By using a study that allows GPs to transmit electronically their findings and data, it is possible to draw a picture of treatment strategies of GPs in patients presenting with rectal bleeding. The high percentage of patients who received medical treatment in consultation with specialists underscores the significance of the sign of rectal bleeding in general practice. The need for further diagnostic measures in patients who have been treated exclusively by GPs has to be discussed.

Keywords: bleeding, colonoscopy, colorectal cancer, general practice, internet, rectal diseases, survey


Change in bowel habits, frequent abdominal pain, and rectal bleeding are common reasons for consulting a GP.1 The symptom of rectal bleeding in particular requires exact diagnosis because it can be an early sign of severe bowel diseases, such as colon carcinoma, or inflammatory bowel diseases. An examination of 99 patients aged over 40 years and presenting with a first episode of rectal bleeding who had been referred for a colonoscopy by GPs, showed serious abnormal findings in 44.9% of the cases.2 An estimated incidence of 8.3 and 7 in 1000 persons per year3,4 underscores the importance of this symptom in general practice.

Exact diagnostics are of crucial prognostic importance for an early detection of a colorectal carcinoma. Screening programmes and prompt treatment of colorectal carcinoma increases the survival time,57 although some doubts remain.8

Although there are many gastroenterological guidelines911 and studies12,13 about detecting colorectal carcinomas, little is known about treatment strategies in general practice. A survey among Australian GPs about treating the symptom of rectal bleeding using case samples revealed a great variety of suggested diagnostic approaches. There was uncertainty about using existing guidelines.14 Olynyk et al remarked that in general practice there is a tendency to over- or undertreat patients with rectal bleeding.15

The aim of the present study is to record the performance of GPs of patients with rectal bleeding. The applied diagnostic measures, cooperation between GPs and specialists, and the final diagnoses are of special interest.


A nationwide research network was established to connect clinical research with the current activities of GPs concerning chronic bowel diseases (Kompetenznetz Chronisch Entzündliche Darmerkrankung). The Institute of General Medicine (Institut für Allgemeinmedizin) in Berlin solicited 2400 GPs in Germany to participate in the study; of these, 116 agreed to participate.

In a prospective study, GPs entered information about patients with chronic bowel diseases into a digital computer template to transmit it via internet or ISDN to the researchers of the study.

The study's five criteria were rectal bleeding, abdominal pain over 21 days, changed bowel habits over 21 days, evidence of bowel-related anaemia, or loss of weight. Patients with known chronic inflammatory bowel disease, a known colon carcinoma, or diagnosed polyps were also included in the study. The participating physicians recorded information about age, sex, occupation, the initial complaints, the ensuing diagnostic measures, and the final diagnoses. Three months before the start of the study the specially designed template was subjected to a feasibility phase to meet the requirements of the participating physicians.

Each participating physician randomly received only three of the five criteria in order to reduce the workload. Patients presenting with at least one bowel symptom and who were aged 15 years or more were included in this study. To draw the picture of managed care as clearly as possible, patients had to meet minimum criteria regarding patient documentation recorded by the participating physicians:

  • entry of at least 7 out of 10 personal data fields,
  • at least one valid detail in the fields of diagnostics, procedure, diagnosis, or therapy, and
  • ability to confirm patient data during monitoring of the study physicians.

How this fits in

Exact diagnostics are of crucial prognostic importance for an early detection of a colorectal carcinoma in primary care. Patients aged 50 years and over with visible rectal bleeding where the presence of colorectal cancer or polyps could not be excluded need appropriate further diagnostic evaluation.

During the course of the study, monitoring was performed to evaluate the quality of the entered patient data by comparing the practice patient files regarding personal data, family history, diagnostics, procedures, and final diagnoses with the data provided for the study. Thirty-five of 116 physicians were randomly selected for visits to validate the quality of the data record.

Every patient signed a written consent form before the beginning of the study. The data collection took place in accordance with the data protection official.

Data management

Data input was performed via an internet-based computer template (‘remote data entry’).

The application server was securely accessed by entering a password to a common internet browser. GPs established a connection to the browser through the computers in their respective individual practices. Data were stored centrally on a SQL server in a relational data model.

Statistical analysis

From the total group of recorded patients presenting with bowel diseases and symptoms, the present analysis only incorporates findings of patients presenting with the first sign of rectal bleeding and associated symptoms, but without pre-existing bowel diseases. The descriptive analysis was performed by the Institute of Medical Information Processing, using the statistics programmes SAS 8.0 and SPSS 11.0. The analysis for free text data was performed in patients where neither a consultation with another specialist nor a colonoscopy was recorded.


Study sample

Over the course of 1 year, 2239 patients with chronic bowel symptoms and diseases were registered by 116 GPs. Ten participating physicians resigned before the end of the study for personal reasons; 12 physicians discontinued due to lack of cooperation. The majority of the participating physicians were between 40 and 50 years old. Two-thirds of them were male and a third were female. The median number of years spent working in general practice was nine. Age, sex, and time in private practice of the physicians who left the study early conformed with those who remained in the study.

All in all, 1969 patients were registered by 94 participating physicians over the course of 1 year. There were 1584 patients who met the minimum requirements and were included in the analysis.

Monitoring of the participating physicians

In order to ensure validity of reported information, 35 GPs' practices were visited and the original patient files studied. The comparison between the data documented in the patient files by the GPs and the data they actually entered into the digital template revealed a concordance of 70%.

Rectal bleeding in general practice

This study presents the results of the 422 patients in whom the GPs recorded the sign of rectal bleeding. The most common accompanying symptoms associated with rectal bleeding (Table 1) were abdominal pain (23.0%), changed bowel habits (17.3%), anaemia (5.5%) and weight loss (3.1%).

Table 1
Main symptoms and work-up of rectal bleeding in general practice.

Diagnostic work-up of rectal bleeding

In response to the sign of rectal bleeding, an abdominal sonography was performed in 54 (12.8%) patients. In 10 patients the examination was conducted by a GP alone, in 15 patients the sonography was performed by both a GP and a specialist. Twenty-eight patients were referred to a specialist — of these, 25 had a sonography done by a gastroenterologist or specialist in internal medicine.

Of the 29 rectoscopies conducted, seven were performed by GPs, 14 by gastroenterologists or specialists in internal medicine, and four by other specialists. In four patients the rectoscopy was conducted by both a GP and a gastroenterologist or a specialist in internal medicine. Of all 26 sigmoidoscopies, seven were performed by a GP, 23 by a gastroenterologist or a specialist in internal medicine and four by other specialists. In eight patients the sigmoidoscopy was conducted by both a GP and gastroenterologists or specialists in internal medicine.

The participating physicians referred 280 patients (66.4%) to specialists (gastroenterologists, radiologists, physicians with special interests); the GPs made more than one referral to specialists for some patients. They conducted 50 admissions directly to hospital for 46 patients (10.9%) during the course of the study.

The most frequently performed diagnostic procedure was a colonoscopy. Of the 195 colonoscopies performed, in 37.4% of the cases (n = 73) the terminal ileum was left unexamined. As predicted, in 268 patients aged 50 years and above, colonoscopies were performed more often (51.9%; n = 139) than in the 153 younger patients (36.6%; n = 56; P<0.003). Rectoscopies (6.9%, n = 29) and sigmoidoscopies (6.2%, n = 26) were rarely performed in the total group of patients (n = 422).

Diagnoses following presentation with symptoms of rectal bleeding

Of all patients presenting with the sign of rectal bleeding, haemorrhoids was the most common newly diagnosed bowel disease (26.1%, n = 110; Table 2), followed by polyps of different grades of differentiation (10.7%, n = 45), diverticulosis/diverticulitis (9.5%, n = 40) and patients with disorders of the upper gastrointestinal tract (8.7%, n = 37). Colon carcinoma was diagnosed in 17 cases (4.0%), inflammatory bowel disease (including Crohn's disease, ulcerative colitis, and undetermined colitis) was detected in 22 patients (5.2%).

Table 2
New confirmed diagnoses following the symptom of rectal bleeding.

For 93 of the patients (22.0%), there was no documentation from their GPs about cooperation with other specialists, nor were further diagnostic measures taken. The analysis of the physicians' explanatory notes for these patients showed that presumable pre-existing bowel diseases, such as diverticulosis, were found in nine of the patients. Additionally, it revealed upper gastrointestinal tract diseases in four patients. The GPs recorded haemorrhoids or other proctologic diseases, such as anal fissures, in 58 patients. Twenty-five of these patients were aged 50 years and above. The course of disease and the diagnostics could not be assessed with the data provided in the explanatory notes in 22 of the 93 patients.

Patients without further diagnostic procedures

Ninety-three patients (54 of them aged 50 years and above) were treated exclusively by their GPs — with no further diagnostic procedure or consultations with specialists.

The additional analysis of the explanatory notes revealed that 27 patients aged 50 years and above were found to have exclusively haemorrhoids or other proctologic diseases as their final diagnosis. For this group of patients, bright red bleeding was the most common first symptom (n = 19), associated with further bowel-related symptoms in seven patients (Table 3). Further analyses of findings revealed that blood mixed with stools (n = 2) and blood on stools (n = 2) occurred more rarely. However, in four patients with haemorrhoids diagnosed by the physicians, the faecal occult blood test (FOBT) screening was positive. One of the patients refused further diagnostic procedures.

Table 3
Symptom pattern of rectal bleeding in patients ≥50 years not referred to a specialist (n = 27).


Summary of main findings

This study investigates strategies of the diagnostic work-up of patients presenting with rectal bleeding in general practice. An electronic link between surgeries and the coordinating university enabled physicians to record their medical procedures concerning patients with rectal bleeding in general practice.

Our findings indicate that the majority of patients presenting with the symptom of rectal bleeding were referred from their GP to a specialist for further diagnostic tests. Colonoscopies were the primary diagnostic measures utilised. Although a complete colonoscopy is desirable,16 the terminal ileum was not examined in 37.4% (n = 73) of all colonoscopies performed (n = 195). It is important to note that in 27 patients aged 50 years and above, GPs diagnosed haemorrhoids and other benign proctologic diseases without having conducted further diagnostics. Four of these patients had a positive FOBT test.

Strengths and limitations of this study

The median number of 9 years spent working in general practice indicates that the survey was performed with experienced GPs. With regard to the number of registered patients with rectal bleeding, after monitoring the GP practices, we found no sign of under-reporting. Taking into consideration that the public has paid more and more attention to the early detection of colorectal cancer over recent years, we conclude that not only patients but also physicians have become well aware of the importance of reporting rectal bleeding. This leads to our conclusion that most patients with rectal bleeding have been documented by the participating GPs. The physicians were able to complete relevant data collection for a period of 3 months following the end of the study. We suggest that no further diagnostic evaluation related to the presentation of rectal bleeding was performed by the GPs during that time.

However, diagnostic procedures of the gastrointestinal tract performed prior to the commencement of the study were not recorded in the survey. It has to be mentioned that some clinical information regarding patients' histories was not entered by the participating GPs. This could have occurred when medical information of specialists was not transmitted back to the GP practice.

Another possible source of error could be the physicians' lack of experience with internet-based data entry and employing the computer template as designed. As the participating GPs randomly received only three of the five entering criteria, an epidemiological conclusion about the frequency of severe diagnoses was not intended from the study's outline.

Comparison with existing literature

Our results point out that GPs undertake a broad number of interventions in general practice to clarify the cause of rectal bleeding. However, for a small number of patients aged 50 years and above, relevant diagnostic measures were not accomplished in relation to positive a FOBT test. One must consider that patients' refusal of colonoscopies were not registered in this study; Lemon et al underlined the importance of patient barriers to further diagnostics after screening for colorectal cancer.16 However, our findings are comparable to findings in other studies where primary care physicians failed to order complete diagnostic evaluation (that is, colonoscopy or combined flexible sigmoidoscopy plus barium enema X-ray) in patients with positive FOBT.17,18 German guidelines recommend a colonoscopy with each positive FOBT test.10

A matter of particular interest was the symptom pattern of rectal bleeding in patients aged 50 years and above without further diagnostic evaluation. The measures taken by the GPs in this study correspond closely to the recommendations of the referral guidelines for suspected cancer of the British NHS.11 It might have been appropriate for most of these patients not to be referred for further investigation, but opinions about the need for further diagnostic measures, particularly in patients aged 50 years and above with visible rectal bleeding, are contrary. It is not possible, merely from an anal examination, to be certain that rectal bleeding necessarily originates from a simple anal lesion, such as haemorrhoids. These lesions may coexist with colorectal adenoma or cancer. Different recommendations concerning further diagnostic procedures in patients with rectal bleeding in association with a change in bowl habits or abdominal pain,11,19 make it complex for GPs to decide whether a referral process might be appropriate or not.

Due to an initiative of German health insurers, patients over the age of 55 years have the option of being referred for a screening colonoscopy even without showing bowel-related symptoms.20 This is an extension to guidelines that recommend investigations based on specific symptoms only. We conclude that patients aged 50 years and above, with symptoms whereby the presence of colorectal cancer or polyps could not be excluded by other means, should have appropriate further diagnostic evaluation.

Implications for future research and clinical practice

Specific clinical indications for colonoscopies or complete diagnositc evaluation could help GPs to decide whether or not to conduct further diagnostic procedures in patients with visible rectal bleeding. Future surveys should address which symptom pattern related to rectal bleeding should undergo additional diagnostic processes.

Funding body and reference number

The present study was made possible in the framework of the network of Inflammatory Bowel Diseases (Reference number 01GI9987/5)

Ethics committee and reference number

Charité Universitätsmedizin ethics board (Reference number 1366)

Competing interests



We would like to offer our thanks to all patients and physicians who took part in this project, and to Klaus Kloch and to Tobias Esch who assisted with note auditing.


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Br J Gen Pract. 2005 January 1; 55(510): 18.


Knottnerus and Dinant coined the phrase ‘medicine-based evidence’ in order to highlight the requirement for research evidence to be generated in the context of real clinical practice.1 Unfortunately, this is a particularly difficult problem to address in primary care due to the dispersed and heterogeneous nature of the speciality.

This article by Heintze and colleagues highlights the potential of using the internet to link together 94 general practitioners spread across Germany with a clinical research hub in Berlin. Using a digital computer template, practitioners prospectively collected clinical data in a standardised format. Furthermore, a third of the participating physicians were randomly selected for visits to validate the quality of the data record.

The authors should be congratulated on their approach and it is interesting to note that a similar method is also being harnessed to research primary care diagnostics in Australia. However, although such internet-based approaches provide a potentially useful primary care clinical research tool, some issues remain unresolved. For example, although Heintze et al invited 2400 GPs to participate; only 94 satisfactorily completed the task. The representativeness of these practitioners and the patients they chose to recruit remains uncertain. It is also unclear whether patients are more likely to be recruited if they experienced a greater severity or number of symptoms.

Heintze et al addressed validity but neglected to consider reliability (reproducibility). Inter-rater reliability is a particular issue in such a large scale study as other work has indicated that some symptoms of possible oncological significance are more reliable than others.2 Clearly, future work should be designed to assess reliability and representativeness in addition to validity.


1. Knottnerus A. Medicine based evidence, a prerequisite for evidence based medicine. BMJ. 1997;315:1109–1110. [PMC free article] [PubMed]
2. Summerton N, et al. Developing clinically relevant and reproducible symptom-defined populations for cancer diagnostic research in general practice using a community survey. Fam Pract. 2003;20:340–346. [PubMed]

Articles from The British Journal of General Practice are provided here courtesy of Royal College of General Practitioners