After giving a stool sample and being diagnosed with intestinal blastocystis hominis, I was prescribed 750 mg of Flagyl daily (250 mg x 3/day). They are white tablets easy to swallow, very bitter to the taste, and you can't drink any alcohol while on the medication.
The first time I took Flagyl (oral metronidazole) it was very effective, even at 500 mg per day. I lost my appetite and completely lost my desire for carbs immediately, and after a couple weeks I started to feel very disoriented and dizzy at times; this progressed to a depression of sorts, my mental state was definitely affected by the Flagyl.
Since 2005 I have gone on four cycles of Flagyl since the blastocystis hominis are very stubborn and always return, relapse is common unless you totally abstain from carbs (ie no bread, potatoes, flour products, sugar or concentrated fruit juices) since blastocysts thrive on carbs and multiply like crazy in your digestive tract UNLESS you counter-attack with extremely potent probiotics. Probiotics are expensive and you have to keep taking them daily.
I made the mistake of not taking probiotics since my doctor never mentioned they were necessary. Doctors can be very vague about things, it never ceases to amaze me how little information they will give you, and how much you have to research on your own, and learn through trial and error.
If you don't take strong probiotics for your digestive tract after treatment with Flagyl, you will probably develop candida infection (a type of overgrowth of intestinal yeast disorder) which will also deliver symptoms of brain fog and burping and gas and embarassing bloating after meals.
I have suffered with this syndrome off and on for over 6 years now and the blastocystis hominis are always hiding waiting to reappear when I eat carbs or drink beer or alcohol (and it is difficult to go through life without bread, potatoes, baked goods, never a glass of wine or beer . . . just clean meat and fresh vegetables and whole fruits are allowed)
Well the Flagyl helped me lose a lot of weight very quickly every time I went on it; last year I lost 35 lbs in four months in conjunction with diet and exercise (Flagyl makes you lose your appetite) but I gained 15 lbs back very quickly once I went off it and starting eating and drinking normally again.
All I can say is that it does work by disinfecting your gut, but feels like drinking Lysol or Pinesol lol, imagine that. It will make you sick for sure in some way, but then antibiotics always seem to have unpleasant side effects and you have to counter these with plenty of probiotics and tons of water and fresh vegetables and plenty of clean protein; and that's not an easy task, considering the average North American diet consists of a lot of restaurant fare and flour-based products.
Many people with digestive problems and gut issues suffer from rosacea as well; I battle ocular rosacea (itching red eyes) and the papules and red breakouts on my chest and upper arms regularly. It's an ongoing battle, probably genetic in nature. Just something you have to keep aware of and eat the right foods, totally avoiding all carbs if possible.