In order to describe the molecular epidemiology of Blastocystis infection in Italy, 189 isolates, which had been collected during the years 2012–2014 from mildly symptomatic patients, or those affected by inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) or chronic diarrhoea, or otherwise immunosuppressed, were subtyped by sequence analysis of the SSU rRNA gene (536 bp). Six subtypes (STs) were detected: ST1 (15·3%), ST2 (13·8%), ST3 (46·0%), ST4 (21·7%), ST6 (3·2%) and ST8 (0·5%). They clustered in distinct clades, as inferred from Bayesian inference phylogenetic and median joining network analyses. A high genetic differentiation was found at the inter-subtype level; it ranged from Jukes–Cantor (JC) distance = 0·02 (between ST1 and ST4) to JC = 0·11 (between ST6 and ST2). At the intra-ST level, a high genetic homogeneity was registered in ST4, whereas higher genetic variation was found in isolates corresponding to ST1 and ST2. Accordingly, high values of haplotype and nucleotide diversity were observed in ST1, ST2 and ST3. No association was found between patient gender and ST, whereas ST3 and ST1 were significantly more prevalent in patients aged 15–50 years. A significant occurrence of Blastocystis ST4 in patients suffering from IBS, IBD or chronic diarrhoea was observed; in addition, a slight significant association between ST1 and ST3 and IBS patients was found. Multiple correspondence analysis showed some significant contribution of different variables (subtypes, haplotypes, age) in the observed pattern of ordination of the 189 patients in the symptom categories.

How do somatic causal attributions for symptoms relate to treatment seeking behaviour in Irritable Bowel Syndrome (IBS)? How might a tendency to make somatic attributions influence an individual's cognitive representation of their illness once a diagnosis of IBS is established? In Study 1 attributions about symptoms were investigated in treatment-seekers and non treatment-seekers with IBS. Treatment-seekers had an increased tendency to make somatic attributions for both gastrointestinal symptoms and physiological symptoms characteristic of anxiety and depression, although they did not differ from non treatment-seekers in the severity of these symptoms or in their reports of psychological distress. Treatment-seekers also perceived themselves to be significantly less resistant to illness and to be significantly more likely to have poor health in the future than non treatment-seekers. In Study 2, 20 treatment seekers with chronic symptoms of IBS completed measures of mood and of the degree to which they viewed a range of symptoms as a part of their IBS. Physiological symptoms of anxiety and depression were seen as a part of IBS by a considerable proportion of the sample. Higher levels of depression were associated with an increased tendency to see physiological symptoms of anxiety and depression and even symptoms of colds as “a part of” IBS. It is concluded that a somatic attributional style may contribute both to initial treatment seeking for symptoms of IBS and the subsequent maintenance and exacerbation of the disorder once a diagnosis is established.