Can gastroparesis cause severe constipation and many undigested food in stool including fat?

I am not sure. Gastroparesis is what the name is saying namely the stomach does not empty and food stagnates there 4 hours. Usually it could be part of paresis of the entire GI tract and in this case constipation could be present. If there are difficulties in digesting too i think is possibly to have fat steatorrhea (fat in stool). As far as i know however fat in stool causes loose stools...See an GI guy!