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Hi Sqad, thanks for explaining, it is appreciated.
They put a bigger one in this time and it has stayed in for far longer so that's been good.
Hoping for a less painful insertion this time, the first few tries they did for the last one were without sufficient local anaesthetic, deeply unpleasant and took me some courage to let them have another go with more anaesthetic in!
Will definitely be getting them to check I'm properly numbed next time.
The grommet does help though, glad I had them put in.