Existing research has shown that patients with Irritable bowel syndrome focus their attention selectively towards words related to gastrointestinal symptoms, socially threatening and contextual words. The goals of this research were to examine the difference in reaction time of recognising colours between different categories of words by using the modified Stroop task, and examining the relationship between reaction time and some aspects of anxiety. Fourty-three people with Irritable bowel syndrome participated in the research (35 F and 8 M), with ages ranging from 21 to 80 years. The participants completed a set of questionnaires and participated in a modified Stroop task. Questionnaire measures of anxiety as a personality trait, visceral anxiety, anxiety sensitivity and anxious thoughts were applied. In the modified Stroop task, participants needed to recognise the colour in which the words were presented: red or orange. Four different categories of words were used: words that describe symptoms of irritable bowel syndrome (e.g. pain, constipation), emotionally relevant words (e.g. fear, isolation), contextually relevant words (words which describe potentially threatening situations for people with irritable bowel syndrome (e.g. going out, lift) and neutral words (e.g. mug, flower). The results did not indicate significant main effects of word category or word colour on reaction time. However, there is a tendency towards a significantly shorter reaction time to contextual compared to neutral words. Out of the examined aspects of anxiety, anxious thoughts are negatively related to reaction time to emotional and contextual words. More precisely, the subscale of social worry is negatively related to reaction time to contextual, emotional and neutral words. Patients with higher levels of social worry recognise the colour of the aforementioned categories of words faster, and, in discussion, the special attention is given to the connection of higher levels of social worry and shorter time of identifying the colour of contextual words. Comments about the results are given within the context of existing theories and previous knowledge. The obtained results build onto existing knowledge and have important practical implications, like better understanding of IBS population and creating adequate psychological treatment.