Editor,—The commentary by Al-Musawi and Williamson (Gut1997;43:454–5) on our paper (Gut1998;43:571–4) in the same issue suggests that there is still a place for cholecystokinin (CCK) provocation tests although the authors fail to provide any evidence to support their statement. Their criticism of our paper relates to numbers of patients in subgroups and histology of the gall bladder, and they seem to have ignored the key message on outcomes after cholecystectomy in these patients as a whole. The only study they have quoted in support of their statement is Rhodes et al’s paper1 which we have discussed in detail as proving that patients who were CCK negative had perhaps better symptom relief than CCK positive patients (89 v 67%). CCK does contract the gall bladder and may cause pain but this has no bearing on symptomatic outcome after cholecystectomy. This is what makes this test useless.