Overlap between irritable bowel syndrome and functional dyspepsia including subtype analyses

Area of Science:

• Gastroenterology
• Functional Gastrointestinal Disorders
• Genetics

Background:

• Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are common gastrointestinal disorders.
• The overlap between FD and IBS (IBS-FD) and its associated risk factors are not well understood.
• Understanding these overlaps is crucial for effective diagnosis and management.

Purpose of the Study:

• To evaluate clinicodemographic features of FD, IBS, and IBS-FD overlap.
• To identify risk factors, including genetic polymorphisms, associated with IBS-FD.
• To clarify symptom profiles and prevalence in overlapping FD and IBS cases.

Main Methods:

• A study involving 632 subjects, including control, FD, IBS, and IBS-FD groups.
• Rome III criteria were used for diagnosing functional gastrointestinal disorders.
• Multivariate logistic regression analyzed risk factors, including 5-HTTLPR, ADRA2A, and CCK-1R genetic polymorphisms.

Main Results:

• IBS-FD overlap patients exhibited more severe symptoms (bloating, nausea, vomiting) and higher depression scores.
• Independent risk factors for IBS-FD included marital status, nausea, bloating, and incomplete emptying.
• Young age, depression, bloating, and postprandial distress syndrome were associated with IBS-FD in FD patients.
• 5-HTTLPR L/L genotype was a risk factor for co-occurring IBS with constipation (IBS-C) in FD patients.

Conclusions:

• Bloating is a significant risk factor for IBS-FD overlap.
• Postprandial distress syndrome increases the risk of coexisting IBS, particularly constipation-dominant IBS.
• Identifying specific risk factors aids in understanding and managing overlapping functional gastrointestinal disorders.