Effect of Meal Ingestion on Ileocolonic and Colonic Transit in Health and Irritable Bowel Syndrome

Background Postprandial symptoms in irritable bowel syndrome (IBS) have been associated with increased bowel contractility. Aim To compare ileocolonic and colonic responses to feeding in health and IBS. Methods We prospectively analyzed data from separate research trials in 122 IBS patients and 41 healthy volunteers. Ileocolonic transit (ICT) was evaluated before (colonic filling [CF]3h) and immediately after (CF4h) a standard lunch at 3 h 45 min, and 2 h thereafter. The colonic geometric center (GC) was calculated 2 h (GC6h) after lunch ingested at 4 h (GC4h) and directly after (GC8h) a standard dinner ingested at 7 h 45 min. Results ICT immediately after eating was higher in IBS diarrhea predominant (IBS-D) patients than in the healthy cohort (23.1 ± 2.4 vs. 17.5 ± 2.8%, P = 0.059). ICT 2 h after lunch was similar between groups (P = 0.55). There was significant overall group differences in colonic transit 2 h post-lunch (P = 0.045), particularly in the IBS constipation predominant (IBS-C; GC6-GC4, Δ0.29 ± 0.08) patients versus healthy volunteers (Δ0.56 ± 0.12 GC units). Conclusions After feeding, ICT is increased in IBS-D, whereas colonic transit is blunted in IBS-C.