Bathroom ?
I heard about the lactose thing too, but it could be some of your sugar free stuff too. Also, to make a correction to the last post, you'll want to make sure they don't contain sugar alcohols, these can cause the runs and abdominal cramps in some people. Sucrose and Sucralose (Splenda) should NOT effect you negatively.
Examples of sugar alcohol are:
- Erythritol
- hydrogenated starch hydrolysates
- isomalt
- lactitol
- maltitol
- mannitol
- sorbitol
- xylitol