Introduction

Chronic diarrhoea is a common problem seen in both primary and secondary care, affecting up to 5% of the general population at any given time.1 Evaluation of chronic diarrhoea poses myriad challenges to the clinician, not in the least because ‘diarrhoea’ means different things to different people (patients and clinicians) but also because it has a diverse aetiology and can be multifactorial in any given individual. Patients relate to loose stool consistency, increased frequency of defaecation, urgency or incontinence (or in combination with one or some of these symptoms) as ‘diarrhoea’ while physicians have traditionally used an increased frequency of defaecation or increased stool weight to define diarrhoea.1

The recent publication of updated British Society of Gastroenterology (BSG) guidelines by Arasaradnam and colleagues addresses this inconsistency, providing a pragmatic definition and approach to the diagnosis and investigation of patients with chronic diarrhoea (figure 1).2 The guidelines define chronic diarrhoea as ‘the persistent alteration from the norm with stool consistency between types 5 and 7 on the Bristol stool chart and increased frequency greater than 4 weeks’ duration’.

The challenges presented by the diagnostic workup of chronic diarrhoea are arguably more pronounced in the elderly, wherein diverse aetiologies in the face of multiple potential clinical comorbidities and polypharmacy for these conditions, and additional limitations posed by frailty and resultant inability to undergo recommended investigations need careful consideration. This article aims to offer a pragmatic approach to the assessment of chronic diarrhoea in the elderly (figure 2).