It’s variable with me. The shortest time to start with me was about 45 minutes! Surprise! I took it after a light supper at 7 PM and was going to read in bed, had just put the night time diapers on when I passed some gas. Half way through the first loose accident suddenly emerged - no warning or even change in feeling as it passed into the diapers. It worked for the next four hours.
Other times it’s been 2-4 hours mostly, but rarely, 6-8.
Castor oil is processed into its active chemical, ricinoleic acid, in the upper intestine with oil-splitting enzymes from the pancreas, and I guess of there’s a good supply of this stuff, things happen more quickly. A meal with some fat and oil probably stimulates the pancreas to let those actions chemicals out to do their work.
I used Clamato for the mix last night just after supper and it started in an hour and a half, and worked all night. There were a lot of gas cramps but I find that pleasant, a harbinger of what’s to come. It’s now 18 hours since I took it and I can feel it’s going to work again soon, but not much left in there.
I’ll have to give chocolate a try, but hope it doesn’t spoil my love of chocolate...