Colonic gas transit and effects of mechanical stimulation on the abdominal wall

OC3.07.5 COLONIC GAS TRANSIT AND EFFECTS OF MECHANICAL STIMULATION ON THE ABDOMINALWALL F. Tremolaterra ∗ , A. Pascariello, D. Consalvo, C. Ciacci, P. Iovino Università Federico II, Napoli Background and aim: Bloating and abdominal distension are frequently reported by patients with functional gastrointestinal disease. Recently it has been suggested that patients with bloating have impaired intestinal handling of gas loads. Aims of our work is study the colon gas handling in irritable bowel syndrome (IBS) and functional bloating (FB) patients by a specific gas challenge test and to evaluate the effects on colon gas transit and bloating symptoms of mechanical stimulation on the abdominal wall. Material and methods: Fifteen patients (12 F, range 27-64y; 11 IBS, 4 FB) and 5 healthy control (4 F, range 20-40y) were assigned, in random order, to study I: colonic gas load (5 patients and 5 healthy control) or study II: colonic gas load + electro-mechanical stimulation of abdominal wall, active and sham (5 patients active and 5 sham). Colonic gas load study was performed by a 60 min continuous gas mixture infusion (N2, CO2, O2 in venous proportion) at 24 ml/min and by its collecting, for other 30 min, via the anal balloon-catheter. The mechanical stimulation on the abdomen was performed by an electro-mechanical stimulator (Free-lax, ADM, Israel) and was applied at active group during evacuation period of the study II. Symptom perception and abdominal distension were measured by a validated questionnaire and a metric belt-tape assembly respectively. Gas retention was calculated as the difference between the volume of gas infused and the volume of gas recovered. Results: Study I: patients developed significantly more gas retention compared to healthy control (586±50ml vs 493±41ml, p=0.01). Further the patients complained a significant more abdominal perception then healthy control either to the end infusion period (60° min) or to the end gas evacuation period (90° min) (4.5±1.0 vs 2.4±0.9 e 1.1±1.0 vs 0±0, p=0.01 e p=0.04, respectively) and more abdominal distension to the end of gas evacuation period (2.4±1.1mm vs 0.2±0.4mm, respectively; p=0.004). Study II: no statistically differences was found in gas retention, perception and abdominal distension, in all study period, among patients with or without electro-mechanical stimulation. Conclusions: Our study shows an impaired transit and tolerance of colonic gas loads in IBS and FB patients not modified by mechanical stimulation of abdominal wall. # M. Functional disorders 2. IBS