Gastroenterology remains the most general of specialties, encompassing psychological, functional, inflammatory and infectious and neoplastic disorders. The last 30 years have seen a major revolution in the way that gastroenterological clinicians think and work, brought about largely by the ready ability to inspect visually, and to biopsy, the upper gastrointestinal tract, colon and terminal ileum. Nevertheless, the relative nonspecificity of gastroenterological symptomatology, the relative inaccessibility of the small intestine (5–6 m in length) and the desire to define simple serological tests continues to provide a major role for laboratory assessments to detect and to assess gastrointestinal disease.

It is convenient, therefore, to assess what the straightforward first-line techniques of clinical gastroenterology can achieve, before considering the role of laboratory assessments. With respect to oesophageal disease, clinical history taking can localize disease in most cases, or at least to the oesophago-gastro-duodenal complex. With suggestive symptoms (reflux symptoms of acid heartburn, dysphagia), most clinicians will rapidly proceed to one of two approaches, both anatomical – endoscopy or radiology – to define the presence or absence of ulceration, inflammation, neoplasia or fibrotic stricture. Similarly, if the patient complains of clearly acid-related gastroduodenal symptoms, there will be rapid recourse to endoscopy.

This approach to ‘acid-related dyspepsia’ will be increasingly complemented with, or replaced by, seeking to identify the presence or absence of infection with Helicobacter pylori, the association of which with duodenal and gastric ulceration, but not with reflux oesophagitis, has become increasingly stressed in recent years.