LAUSR

BACKGROUND Prolonged or recurrent gastrointestinal symptoms may persist after acute traveller's diarrhoea, even after adequate treatment of the primary cause. This study aims to describe the epidemiological, clinical, and microbiological characteristics of patients with post-infectious irritable bowel syndrome after returning from tropical or subtropical areas. METHODS We conducted a retrospective study of patients presenting between 2009 and 2018 at the International Health referral center in Barcelona with persistent gastrointestinal symptoms following a diagnosis of traveller's diarrhoea. Post-infectious irritable bowel syndrome was defined as the presence of persistent or recurrent gastrointestinal manifestations for at least six months after the diagnosis of traveller's diarrhoea, a negative stool culture for bacterial pathogens, and a negative ova and parasite exam after targeted treatment. Epidemiological, clinical, and microbiological variables were collected. RESULTS We identified 669 travellers with a diagnosis of traveller's diarrhoea. Sixty-eight (10.2%) of these travellers, mean age 33 years and 36 (52.9%) women, developed post-infectious irritable bowel syndrome. The most frequently visited geographical areas were Latin America (29.4%) and the Middle East (17.6%), with a median trip duration of 30 days (IQR 14-96). A microbiological diagnosis of traveller's diarrhoea was made in 32 of these 68 (47%) patients, 24 (75%) of whom had a parasitic infection, Giardia duodenalis being the most commonly detected parasite (n = 20, 83.3%). The symptoms persisted for a mean of 15 months after diagnosis and treatment of traveller's diarrhoea. The multivariate analysis revealed that parasitic infections were independent risk factors for post-infectious irritable bowel syndrome (OR 3.0, 95%CI 1.2-7.8). Pre-travel counselling reduced the risk of post-infectious irritable bowel syndrome (OR 0.4, 95%CI 0.2-0.9). CONCLUSIONS In our cohort, almost 10% of patients with travellers' diarrhoea developed persistent symptoms compatible with post-infectious irritable bowel syndrome. Parasitic infections, mainly giardiasis, seem to be associated with post-infectious irritable bowel syndrome.