There is a farily upvoted question hene (and so are answers to it) on whether "Does hypnotherapy/hypnosis, in any form, for any type of disorder, work?". To me, that's a pretty weak and confusing question to ask. You can interpret it as "is hypnotherapy better than no therapy", which is quite a different question than "does hypnosis enhance (or not) another therapy, i.e. is hypnotherapy better than (a similar enough) non-hypnotic therapy". The latter question is in some sense superior because it tries to isolate whether hypnosis is worth the hassle when you can also do without.
And the studies I could find on this latter contrast are not as clear-cut as one would like. An 1995 meta-analysis on various conditions reported that hypnosis significantly improved outcomes, but a re-analysis a year later of just the obesity subset showed that the initially reported meta-analytical conclusion critically hinged on one study that was an outlier in terms of the effect size it reported; upon exclusion of that study the overall result lost statistical significance. Furthermore this re-analysis found numerical errors in the original one. From this, it's unclear to me whether the conclusion of the 1995 meta-analysis is tenable for any illnesses.
Likewise a 2012 review of CBT vs CBH for anxiety disorders could not really come to a conclusion and called for more research.
So--my question is--is there an illness for which hypnosis unequivocally enhances treatment outcomes compared to a similar enough non-hypnotic therapy? By unequivocally here I mean at least a review based on several studies deemed of reasonable quality.