Information on Belly Bands
You can get them at any pet store or online (Petsmart has a good one) There are also custom belly bands that are $6 each that are cuter on Etsy.com at a store called Codys Haven (She will make any band in any pattern you like). You will need at least 2 so if one gets wet or dirty you have another till you wash the other one. Bichon's (between 12-18 lbs) will need size XL for the custom bands from the Etsy lady. But if you are getting them from Petco or Petsmart... those bands you will need a MEDIUM. The ones from Petsmart are better than the ones from Petco (Petco's tend to not stick as well after washing).
All you have to do is put a Depends, Poise or CVS type Incontinence pad in them and the pee goes in the pad and no where else. If they pee a lot or you are not home for extended periods, then getting the Large or Extra Large Absorbancy pad is best. Make sure his little wee wee is completely covered / inside the belly band and not sticking out.
Make SURE you get MALE DOGGIE WRAPS and not DIAPERS (Diapers are for GIrl Dogs and are made different) Here is a video on how to use them (Some people just use the belly band with no pad in them, but I don't recommend that as you will be washing them over and over every few hours or it will leek) Make sure you put a PAD inside the belly band.