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.

PURPOSE: This study examined the effect of different intensities of acute exercise on attention allocation to visual food cues, postexercise energy intake, and subjective measures of hunger in women. METHODS: This crossover study utilized treatment conditions that were randomized and counter-balanced. Fifty-two adult women, 18-29 years, were compared under three separate conditions: no exercise, 45 min of moderate-intensity exercise at 3.9 METs and 22.5 min of vigorous-intensity exercise at 7.8 METs. To measure attention allocation to visual food cues, participants were shown a passive viewing task consisting of a continual stream of pictures of food (high and low calorie) and nonfood stimuli while brain activity was monitored using an EEG. The late positive potential (LPP) component of the scalp-recorded event-related potential (ERP) was used for data analysis. Postexercise food intake was measured during an ad libitum snack offered at the end of each condition. Subjective ratings of appetite were measured before and immediately after each condition using a visual analog scale (VAS). RESULTS: No significant differences for LPP were found for the condition (no exercise, moderate exercise or vigorous exercise) by picture type (high calorie, low calorie or nonfood) interaction (P = 0.184). Total kcal intake did not differ among the different exercise conditions (P = 0.19). However, even though energy intake did not differ among exercise conditions, low-energy-dense foods were consumed at higher rates compared to high-energy-dense foods after the vigorous (P = 0.0005) and moderate exercise conditions (P = 0.02) compared to the nonexercise condition. Findings from the VAS indicate the moderate exercise session resulted in significantly higher ratings of hunger when compared to the nonexercise (P = 0.04) and vigorous exercise sessions (P = 0.0046). There was also a significant condition (no exercise, moderate exercise or vigorous exercise) by period (pre- or postexercise) interaction found in postexercise ratings of hunger (P = 0.018). The moderate exercise condition reported higher levels of hunger after exercise (P = 0.0002). In addition, findings from the VAS also indicated energy for the moderate exercise condition increased postexercise (P = 0.006) and was higher than either the nonexercise (P = 0.011) or the vigorous exercise conditions (P = 0.017). CONCLUSION: The results of this study demonstrate that an acute bout of moderate exercise may increase subjective hunger and overall energy without increasing the neural response to visual food cues or postexercise energy intake. Furthermore, it also shows that an acute bout of vigorous exercise did not alter neural response to visual food cues, hunger or energy intake postexercise.