How much can depends hold ?

how much can the depends adult diapers hold? i just don't feel like getting up sometimes and i don't care, i just want to know that if i take a huge dump they will hold it and not leak i work in a very prestigious law firm and can't smell either will they hold the smell in ? or could i put a glade plug in down there not the whole thing just squeeze the juice out of a refill. i also need to know how long i can go before i need to change it ? if i have to stay all day and work into the night will that be a problem? sometimes after work i just crash because i'm so tired so i might not be able to change them till the next day. i usually drink a gallon of water a day and have tails with the girls after work i don't eat much but i do believe in 3 square meals a day even though it usually is McDonalds so any help here will be great thanks !