We always had some in the pantry too, and like OC says, it was brilliant for tummy upsets and very soothing for 'ladies tummy aches'.
I've never thought about it for years, so I'm also wondering where it could be bought. Have you asked at the Chemists OC? The pharmacist might have some ideas being as it was designed for medicinal purposes.
Mind you I think you'd need to find a pharmacist who was getting on a bit as I imagine the younger end will look at you 'gone out'!