Background: Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder causing abdominal pain, altered bowel habits and bloating without structural issues. Gallbladder dysfunction may be linked to IBS due to disrupted cholecystokinin release. This study aims to assess gallbladder function and related hemodynamic parameters using Doppler ultrasound in IBS before and after meals.
Method: In this case-control study, we investigated gallbladder function differences between constipation-predominant IBS (C-IBS) patients and healthy volunteers. Participants underwent ultrasonography to measure gallbladder parameters before and after consuming a predefined meal. Gallbladder volume, wall thickness and resistance index (RI) of cystic and superior mesenteric arteries (SMA) were assessed. Student t-test and paired t-test were used to compare case and control groups and pre- and post-meal data, respectively.
Results: A total of 34 people (18 C-IBS and 16 healthy control) were included. The mean (Standard deviation) of gallbladder fasting volume was measured 24.74 (8.85) and 29.73 (9.65) cubic millimeter for case and controls, respectively. Postprandial volume was 11.34 (5.66) and 16.9 (6.16) cubic millimeter for case and controls respectively. We observed a statistically significant difference in emptying fractions (EF) between groups (p value = 0.009). IBS patients had a smaller fasting SMA RI (p value = 0.016) but the fraction of change after meal was not significant (p value = 0.10). The cystic artery RI did not reach statistical significance between the fasting and post-meal values (p value = 0.067).
Conclusion: IBS patients have a higher emptying fraction and lower change in SMA RI compared to healthy controls. Further studies with larger sample size, inclusion of patients with different coexisting conditions and subtypes of IBS and combining colon transit study with gallbladder ejection fraction evaluation can be used to further provide more meaning to this study.
Keywords: Irritable bowel syndrome; cystic artery; gallbladder; superior mesenteric artery.