How fast does Zentel work?

My 3 ltni son for 2 weeks has problems with dealing with 3 days diarrhea later he settled normally later in a few days vomited now again 3 days he had diarrhea. We did fecal studies and it turned out that the eggs of glizdy people came out. Yesterday at noon he received the zentel of the whole bottle at once and in inches in two weeks. Today he settled once a little normal and at the end mushy. How long can such abdominal ailments last?