Non-invasive biomarkers which identify different mechanisms of disease in subgroups of irritable bowel syndrome (IBS) could be valuable.
Dr Robin Spiller and colleagues from the United Kingdom evaluated whether useful magnetic resonance imaging (MRI) parameters that could distinguish each IBS subtypes.
The team noted that 34 healthy volunteers, 30 IBS with diarrhea, 16 IBS with constipation, and 11 IBS with mixed bowel habit underwent whole-gut transit, and small and large bowel volumes assessment with MRI scans from 0 to 360 minutes.
Since the bowel frequency for IBS with mixed bowel habit were similar to IBS with diarrhea, IBS with mixed bowel habit and IBS with diarrhea were grouped together and labeled as IBS non-constipation group.
|Whole-gut transit time for IBS with constipation was prolonged at 69 hours |
|American Journal of Gastroenterology|
The researchers noted that fasting small bowel water content in IBS non-constipation group was 21, significantly less than HV at 44 ml, as was the postprandial area under the curve.
The fasting transverse colon volumes in IBS with constipation were significantly larger at 253 compared with HV, IBS non-constipation group whose values were 165 and 198 ml, respectively.
The research team found that whole-gut transit time for IBS with constipation was prolonged at 69, compared with HV at 34, and IBS with diarrhea at 34 hours.
Bloating score correlated with transverse colon volume at 405 minutes.
Dr Spiller's team comments, "The constricted small bowel in IBS non-constipation group, and the dilated transverse colon in IBS with constipation point to significant differences in underlying mechanisms of disease."