Should I be concerned if I am not getting a lot of wet diapers but he's drinking?

I am concerned there is something wrong, my son was sick for 4 day with diarrhea and vomit once he was drinking this whole time but not eating like normal, now today he had diarrhea and only 2 maybe 3 wet diapers and has not been to into drinking he is drinking but not like he usually does (this boy can drink). Should I be concerned or as long as he is drinking something should I let it run its course?

placeholder text for bug in Chrome