P245 Influence of activity of ulcerative colitis in the orocecal transit time measured by H2 breath test after administration of lactulose
F. Casellas*1, 2, P. Rodríguez2, A. Aparici2, M. J. Pérez2, V. Robles1, C. Herrera de Guise1, N. Borruel1
1Hospital Universitari Vall d’Hebron, Unitat Atenció Crohn-Colitis, Barcelona, Spain, 2Hospital Universitari Vall d’Hebron, Barcelona, Spain
Ulcerative colitis is characterised, amongst others, by diarrhoea. A mechanism that could be involved in the pathophysiology of diarrhoea is the acceleration of the intestinal transit. However, there are data that suggest the existence of intestinal hypomotility in ulcerative colitis. The reference test to measure orocecal transit time (OCTT) is H2 breath test. It has been suggested that with the use of solid food or 10–20 g of lactulose, TTOC in colitis is slowed, and it can accelerate with olsalazine. The lack of information on the influence of activity of ulcerative colitis on the OCTT measured using low doses of lactulose has stimulated the design of this study.
OBJECTIVE: To measure OCTT by using H2 breath test with low doses of lactulose in active and inactive ulcerative colitis.
We conducted a cross-sectional observational study using the H2 breath test with 5 g lactulose in patients with ulcerative colitis, comparing the OCTT obtained in patients in clinical remission with those in mild or moderate relapse. Patients with total colectomy were excluded. Exhaled alveolar air samples were collected every 10 min for 3 hours, in which the concentration of H2 were measured by gas chromatography.
In total, 96 patients (59 in remission and 37 active) have been included. The total production of H2, expressed by the area under the curve was the same in both groups. The rate of non-producing H2 did not differ significantly between both groups (44% vs 43%). However, the TTOC was significantly slower in patients with active colitis (median 130 vs 90 min in colitis in remission, p < 0.01).
The results of present study using the H2 breath test with low doses of lactulose show that active ulcerative colitis is associated with a slowing of intestinal transit.