The Gastrointestinal Symptom Rating Scale has a Good Test–Retest Reliability in Well-Trained Athletes With and Without Previously Self-Identified Gastrointestinal Complaints

Athletes often report gastrointestinal (GI) complaints. Standardized validated tests validated in athletes are lacking.

The objective of the current study was to investigate the test–retest reliability of the gastrointestinal symptoms rating scale (GSRS), a disease-specific instrument of 15 items to quantify the severity of various GI symptoms.

For this purpose, a 3-week repeated measurements design was used. The mean difference (Wilcoxon signed rank test), associations (Spearman correlations), and systematic difference using Bland–Altman calculations for repeated measurements, as well as its internal consistency (Cronbach’s alpha) on testing day 1 and day 2 were analyzed, with significance set at p ≤ 0.05. A total of n = 70 well-trained athletes (26.1 ± 5.4 years, of which 40% were female) were included.

A high Cronbach’s α for GSRS was found on testing day 1 (0.825), and day 2 (0.823), suggesting a good and comparable internal consistency of the questionnaire. When assessing the multilevel temporal stability for total GSRS scores (28.0, IQR 22.0–36.3 vs 26.5, IQR 18.0–35.0), there was a small but significant difference (Z =  − 2.489, and p = 0.013), but a fair correlation between day scores (r = 0.68, p < 0.001), and a Bland–Altman reporting difference between questionnaires within 10% of the total GSRS score, without significant reporting bias (p = 0.38). In most cases, except for hunger, burping, and loose stools, the individual GSRS items were reported in line with total scores and similar for sex.

In conclusion, the GSRS is reliable when used with athletes, with good internal consistency for most symptoms independently of sex, except for hunger, burping, and loose stools.