How to code vomit event as absorption lag and lost of amount in administration comp.

Dear all, Could someone please give me some tips coding vomitting event as an absorption lag and bioavailability decrease? It's a single dose oral solution with slow absorption. From data I noticed that the time of vomitting was at least 4 hour after dose. Some subjects had mutiple vomitting events. The exposure was noticed a delay after each vomitting compared with non-vomit subject. I have very limit data, and need a good fiitting for the plasma concentration to focus on the pd model. Is there any similar model reported in the literature? Much appreciate for your help! Best regards, Galadriel