Well why not this:
(and there are probably errors in my syntax, but you get the idea):
SELECT * FROM table WHERE ($id LIKE '%,$srch,%') OR ($id LIKE '$srch,%') OR ($id LIKE '%,$srch')
Now you might be wondering why I didn't write it like this:
SELECT * FROM table WHERE ($id LIKE '%$srch%')
Because if you are looking for ID of 125, it will also find id's 1256 and 51259 and 5441250... etc. You have to look for it if it's the first number, or if it's in the middle, or if it's the last number.
-b