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Generations of medical students and trainee doctors have been taught that digital rectal examination (DRE) is an essential part of the clinical examination required in any patient with abdominal pain suspected of having abdominal or pelvic pathology. The aphorism ‘if you don’t put your finger in it you will put your foot in it is familiar to all. But is this now outdated advice? In these days of advanced and readily available imaging techniques, is it appropriate to subject patients to an undignified and unpleasant examination that may contribute little to the diagnostic process?
Before condemning DRE to the history books, it is instructive to consider what information it might provide. In his classical monograph, ‘the early diagnosis of the acute abdomen’ by Sir Zachary Cope first published in 1921, he described rectal examination as ‘extremely important and informative. Forwards in the male one can detect an enlarged prostate, a distended bladder or disease of the seminal vesicles. In the female one can palpate swellings of Douglas’ pouch, enlargements and displacements of the uterus. By passing a finger upwards, stricture of the rectum or ballooning of the canal below obstruction can be ascertained. The apex of an intussusception may sometimes be felt. Laterally, tenderness due to a swollen inflamed appendix or abscess can be elicited. Posteriorally, will determine any tumour or inflammatory mass on the pyriformis or in the hollow of the sacrum’. 1
Small wonder then with such a plethora of diagnostic opportunities that DRE was regarded as a mandatory part of any clinical examination.
Accepting that the experienced digit of a colorectal surgeon or urologist may well discern nuances on DRE that are valuable pointers to appropriate investigation and diagnosis, the question remains as to whether the non-specialist clinician has anything to gain by subjecting the patient to what is always an undignified and on occasions a painful examination. This applies, in particular, to DRE in the context of primary care or in the Accident and Emergency department in patients presenting with abdominal pain.
The evidence strongly suggests that routine DRE can no longer be justified in evaluating patients with acute abdominal pain. Many retrospective observational studies have been reported, none of which recommend the continued use of DRE. The only published systematic review and meta-analysis was by Takada et al in 2015. They followed the standard guidelines for a systematic review of diagnostic studies. They searched the usual databases from the earliest available date of indexing until November 2014 with no language restrictions. They included all studies where DRE was the test under investigation. The gold standard outcome was histologically proven appendicitis Exclusion of appendicitis was also based on histology or refuted by evaluation in follow-up clinic. A total of 19 studies comprising 7511 patients were included after assessing 79 full-text articles. The studies were a mixture of retrospective and prospective studies and included all age groups. The pooled sensitivity was 0.49 (95% CI 0.42 to 0.56), the pooled specificity was 0.61 (95% CI 0.53 to 0.67), the pooled positive likelihood ratio was 1.24 (95% CI 0.97 to 1.58), the pooled negative likelihood ratio was 0.85 (95% CI 0.70 to 1.02) and the diagnostic OR was 1.46 (0.95 to 2.26). Overall, the analysis confirmed that DRE is poor as a diagnostic discriminator in patients with suspected appendicitis.2
A similar picture emerges for the diagnostic utility of DRE in non-specific abdominal pain. In 2004, Manimaran and Galland demonstrated in their prospective sample of 100 patients, that routine performance of DRE did not alter the initial diagnosis or the initial management plan in any of the patients. They showed from their questionnaire that patients regarded DRE as unpleasant and it caused significant embarrassment.3
In 2008, Quaas et al reported a prospective observational study on the utility of DRE in assessing undifferentiated abdominal pain in the emergency department setting. They defined undifferentiated abdominal pain as abdominal pain of previously undiagnosed aetiology. Of the 538 patients (60% of the sample size) who had DRE, in 494 patients (92%) the examination was described as ‘not useful’. Of the remaining 8% in whom the examining clinician thought the examination was helpful, this was not confirmed after review of the final diagnosis. The study concluded that DRE had failed to benefit any patient.4 A systematic review by Werner et al in 2013 which examined six studies reached similar conclusions. They found a positive likelihood ratio of 0.78 to 1.61 and a negative likelihood ratio of 0.91 to 1.29.5
It appears, therefore, that the diagnostic utility of DRE is it at best questionable. Add to this the fact that in recent years, in most modern hospitals, patients presenting with abdominal pain are invariably referred for some form of abdominal imaging further undermines clinical reliance on this intervention. The fact that modern surgical texts no longer advocate routine DRE in all cases suggests that this is becoming the new clinical standard.6
It seems reasonable to conclude that routine DRE, in the assessment of patients with abdominal pain, is no longer justified in primary care or the A and E department particularly when performed by the non-specialist clinician. Further, when management decisions such as the need for imaging or theatre have already been made, then there is little if anything to be gained by subjecting the patient to an unpleasant internal examination.6
But, DRE will remain an essential part of the clinical examination of specialist surgeons and in all patients presenting with anorectal pathology or rectal bleeding. As such, we need to continue to teach what it might reveal.
Contributors OAAE: involved in carrying out the literature review, drafting the manuscript and in the final approval and submission for publication. JM: involved in drafting the manuscript, revising the draft, final approval and the submission for publication.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.