Classification of gastrointestinal symptom patterns in young adults

The purpose of this study was to identify common gastrointestinal (GI) symptom groups using the Patient-Reported Outcomes Measurement Information System - GI symptom scales (PROMIS-GI) within a large sample of young adults. An attempt was made to relate the emergent groups to the Rome IV disorders of gut-brain interaction symptom domains. The PROMIS-GI is a freely available, adaptable, normatively referenced symptom measurement system that is applicable to many health assessment situations.

Participants were 956 introductory psychology students between the ages of 18 and 25 who completed the PROMIS-GI as part of ongoing research monitoring physical and psychological health of students at a major southeastern university. GI symptom groups were determined using a latent class analysis (LCA) approach. These GI symptom groups were then compared on key psychosocial factors including self-reported mood, anxiety, and health related quality of life (HRQoL) using MANOVA.

Three groups were identified based on GI symptom elevations: Normal (n = 649), Mild (n = 257), and Moderate (n = 50). Self-reported anxiety, depression, and bodily pain levels were significantly higher in the Mild and Moderate GI symptom groups, and they indicated significantly lower work functioning, and general health ratings compared to participants in the normal group.

Approximately a third of young adults surveyed were experiencing at least one GI symptom of a severity greater than normative levels. Both the Mild and Moderate GI groups demonstrated a similar configuration of symptoms with significantly the higher levels of pain, gas/bloating, and nausea/vomiting compared to the Normal group. The configuration of symptoms did not map discretely onto the Rome IV diagnostic categories for Bowel Disorders, such as IBS with predominant Diarrhea or Functional Constipation as might be expected. Rather, the emergent groups suggest that Bowel Disorders occur on a continuum of severity across multiple symptom areas. Mild to moderate GI symptoms appear to emerge at much earlier ages and are more frequent than previously documented. It is recommended that health service providers evaluate individual patterns of "GI health" when young adults present with anxiety and depression, and conversely, they should assess anxiety and depression when they present with GI complaints.