Hi
Loperamide is the generic name for Imodium and several other anti diarrhoeal drugs that can be bought in any pharmacy in the UK ( arret, diocalm etc).
Please can I say that these drugs must be used with extreme caution - if you have the trots its your bodys way of getting rid of something that is harming it , loperamide and other such drugs act by slowing down gut movement allowing fluids to be absorbed and things to bulk up. They are fine as a one or two off doses but you should seek advice if the symptoms persist. Loperamide or similar should never be used if there is fever, blood or any suspiscion it is a bug such as salmonella or e coli as if not expelled these can be absorbed and make you very , very ill.
Sorry if this sounds a bit off a rant , and I do know how tummy upsets can spoil a holiday but please be careful