I just read this post that might explain things a little better:
"Some are dead and some are just stunned and poisoned. It depends on where in the body they were when the herbs got to them. For example: if Ascaris larvae are removed while incubating in the lungs, they are dead and mostly decomposed by the time they are eliminated. If adult Ascaris are in the colon area when the herbs hit them, they might be "half-dead" stunned and sick but still squirming a little in the stool.
Most of the time, the body decomposes visible parasites to a nearly unrecognizable state so that by the time they are eliminated - unless you know specfically what you are looking for - you can't tell them from regular fecal matter"