I almost lost my ability to eat food and almost needed a jejunostemy bag and tube because I had such bad GI infections, starting with parasites.
Giarda
Roundorm
Fungal overgrowth
SIBO
I had it all. Usually one leads to the other since the microbiotic environment in the gut is disturbed by parasites, and antibiotics can potentiate fungal overgrowth. It's a tough treatment if you have a bad case.
The best thing is Albendazole. It's better than mebendazole. More systemic and broad spectrum. From experience, the 1 dose of either drug is bullshit. I took albendazole for 2 weeks straight, 1 week off, then 1 week on. Then waited about 4 weeks and did another 5 days of it. 400mg BID.
I expelled worm residue for the entire first week. So 1 dose wasn't going to do anything.
I recommend taking Oreganol with the albendazole, eliminating fructose, limiting or eliminating starch and most fiber. Eat mainly a meat based diet and for carbohydrate drink dextrose with your meals. It is absorbed quickly and high up in the GI so it's less likely to feed the bugs.
I recommend 100-150mg fluconazole while on the albendazole also. 2 weeks on MAX then rest since these drugs can tax the liver a little. If you have worms or other parasites, you probably also have some fungal overgrowth.
Take NAC - it helps both the liver and to break down the biofilms on these pathogens.
Get some VSL #3 and take 4 pills per day for 2 months straight starting right away, and then take 2 pills per day (morning, empty stomach) for as long as you feel it helps. Competitive inhibition through both the transient and populating effect of these probiotics is real. They made a huge difference for me. I couldn't take them until I cleared my SIBO though because they made it worse. If they make your issues worse, wait until you are on the diet mentioned above for several weeks, with the oreganol, and then add them in. Also take Florastor and see if you tolerate that as well from the beginning. If not, add it in after a few weeks on the diet and oreganol.
Take magnesium (glycinate is a good form) to keep peristalsis functioning normally so you can clear the dead stuff. Most of the time pathogens exist in groups, not in isolation. Enemas can help too but I never did them.
Beating serious GI infections from parasites or other pathogens is not easy, and many people never fully recover and live with candida overgrowth, sibo or other thigns that doctors write off as "idiopathic acid reflux" or "IBS" based on symptoms and poor diagnostics.
For lab tests, skip the quest/labcorp micro- analysis bullshit tests and go with metametrix labs DNA stool analysis.
I was horribly ill for an entire year and only the AAS I was on kept me from wasting away into nothing.