FIGURE 2.

Venn diagram of concepts elicited for Crohn's disease (CD) and ulcerative colitis (UC). The concept elicitation exercise identified a total of 141 concept codes (80 symptoms and 61 impacts) relevant to CD and 128 concept codes (79 symptoms and 49 impacts) relevant to UC. Based on the cognitive comprehension exercise, literature review and expert option, 31 concepts (14 symptoms and 17 impacts) were identified for inclusion in the CD instrument and 29 concepts (16 symptoms and 13 impacts) were identified for inclusion in the UC instrument