Get yourself some good pineapples, hopefully a bunch of them, and make sure they are ripe just because it's easy to drink the juice when it's sweet. You can also get red papayas.
Eat basically normally, and if you can, or if you have any junk food cravings in the way of sweets then it's a good idea to indulge somewhat during this.
Also make some very strong ginger tea or strong peppermint oil tea/capsules to break up the gas and bloating.
Try to consume at least 2 quarts per day of fresh pineapple juice. Or concurrently eat a large amount of fresh papayas with a few seeds too blended in. The seeds are very strong so it may be difficult. Eating junk food along with this routine I found actually helps because it allows the worms to relax and helps with peristalsis and it may act as bait.
Give it a go for maybe a week or so and see what happens. If you can get more than 2 quarts down then it's good. Just make sure the pineapples are very sweet and ripe and it will easy to do aside from any die-off that happens.
This will not give you any relief from giardia though, just roundworms.
Ginger tea can be a regular thing for you too if you find that it helps the bloating.
Now also I have found pineapple juice to be more effective than most of the digestive enzymes available. So this could also provide you a way to wean off the pills and then be able to take a stool test
something to keep in mind as well is that we are not living in the year 1960 anymore. People who live near military bases or are around the military are highly likely to be swimming in DU. You should get yourself a geiger counter and check yourself, clothes and surrounings thoroughly.
Some people think that giardia is not pathogenic. I don't know. I'm pretty sure that some of the lesser protozoans are susceptible to all types of bitter substances which would include Wormwood , quinine, turmeric, and anything strongly bitter to the taste.