Q. One who is lo alenu sick with a digestive system disease, and often gets nauseous, or in need to vomit and finds it hard to eat. If he eats a kezais of matza at that time does he comply with the mitzva? Is it maybe seen as eating an achila gassa or overeating and he does not comply and has to wait until better and repeat?
A. As advised in question 2124, in need situation one may eat for the seder a smaller quantity of dampened matza.
Horav Shlomo Miller's Shlit'a opinion is that if the above does not help much, and if the patient was still able to swallow the matza even when nauseous, he complies after the fact in a case of need.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit'a