A UK Survey of Laboratory-Based Gastrointestinal Investigations

Abstract

A survey of hospital laboratory services has demonstrated marked deficiencies in the performance of gastrointestinal function tests. The repertoire of gastrointestinal investigations available varies widely between laboratories and, in general, analyses are performed infrequently. Most laboratories do not perform internal quality control, and inter-laboratory reproducibility of some analytes is very poor. A wide variety of protocols and reference ranges are in use, many of which are unevaluated. Some analytical methods and protocols in current use are outdated, with published improvements not being applied.

Measurement of breath hydrogen and methane, together with lactase genotype, defines the current best practice for investigation of lactose sensitivity

“…2,31,35 All CC/GG patients had a low lactose threshold complaining mainly of gut-related symptoms after lactose, consistent with 100% correlation with raised breath hydrogen. Our data substantiate the claim 16,21,37 that the breath hydrogen test alone is both specific and sensitive, but only for the CC/GG lactase non-persistent cohort of patients ( Figure 2 and Table 1). Our data clearly show that there is no requirement to breath hydrogen or methane test CC/GG lactase non-persistence genotypes ( Table 2; Figures 1 and 2).…”

A Comparison of Lactulose Breath Hydrogen Measurements with Gut Fermentation Profiles in Patients with Fungal‐type Dysbiosis

“…We have, however, fully reproduced our technique. It is important that this should be done as a recent review of laboratory measurements in gastroenterology comments that some laboratories use protocols which deviate significantly from published versions and are probably invalid as a result [20].…”

Faecal fat: time to give it up

“…Currently in the UK, various fat loads and procedures are used. 5 It is clear that larger fat loads (for example, 60 g) result in signi®cant delays in peak 14 CO 2 breath levels. 7 Our procedure uses a fat load of 19´3 g prepared as a palatable lemon mousse, containing protein (1´4 g) and carbohydrate (10 g).…”

“…The author's district offers faecal microscopy or the 14 C-glycerol trioleate ( 14 C-triolein) fat absorption test. 12 In the 1997 survey, 5 performance of faecal microscopy was very poor (sensitivity 26%, speci®city 64%); however, several studies have reported high sensitivity and speci®city ®gures when compared with those derived from faecal fat measurement. 13,14 Some have argued that faecal microscopy after staining with Sudan III has advantages over faecal fat measurement, because it detects faecal triglycerides and fatty acids, which are principally of dietary origin; faecal fats include phospholipids and cholesteryl esters, which largely originate from the turnover of intestinal epithelial cells and gut bacteria.…”