Orlistat advice, please

I've been given Orlistat by my diabetes dietician and am keen to get started. BUT I'm due to meet my son's in-laws-to-be for the first time on Sunday (14/07/13) , having been invited to their house for a meal. No way can I go along and either not eat their food, or run to the loo every couple of minutes.
If I start the Orlistat tomorrow, and do thurs, fri, and sat, would I still be ok to eat whatever I'm given if I just don't take it for Sunday then start properly on the Monday? Or does it build up in the body so that its continuously working and even if I don't take them the effect is still there.
I should have asked the dietician and now she's not back in work til Monday. Also can't find information like this on the Internet as it probably needs experience to answer.

I see from the forum that not everyone agrees with taking Orlistat but I really do want to give it a go. Thanks in advance for any help. It's a great forum and members have really helped me in the past.

Yes, I think that's def the best thing to do. Thanks, Ambersliva, for reinforcing what I thought. In the meantime I'm gonna eat as little fat as poss to get ready for the pills.

Oops, sorry! That's Ambersilva!

Quick update. Although I'd been on the Atkins diet a few years ago for my daughter's wedding, and it was really good, low carb just wasn't working for me this time. I don't know why that should be, unless its to do with age, or being on more meds.
The dietician gave me Orlistat and I've kept to low fat, mostly out of fear of the consequences, and so far I've lost 5lbs without any bowel disruptions. So pretty pleased! Also feeling a lot better in myself, more energy, and I've even joined the local gym.
The main disadvantage with Orlistat I've found, is with wind; sometimes I'm a source of great entertainment to family and visitors as even quite small changes in sitting position can bring forth very loud trumps!
The main advantage, apart from weight loss, is that my sugars are much better; my morning sugars are usually between 4 - 6 and I'm eating a lot less.
So I don't think it's a case of low-fat versus low-carb, and there's not much point in advocates of each putting down the other method. Do what works for you and enjoy the weight loss as it comes!