You are waaaayyy over thinking this whole thing. Bottom line it's gonna be what it's gonna be and each MC you do will be diferent according to the specific need your system has at the time of that particular MC. Just stay with the protocol as written. The first line of defense is to significantly up your fluid intake both water and lemonades to help eliminate toxins. While Burroughs is dead set against enemas in extreme cases of illness many folks have reported instant relief from doing a plain water enema.
Unless the other syrup you got was tainted with bacteria or chemicals it's highly unlikely that it will be the cause of any maladies. The syrup is not part of the cleansing ingredients and it's there for nutritional support to supply carbs and minerals for energy. Any ill feeling are not gonna be caused by the syrup or what you do with the lemons unless there is some kinda contamination. It's simply detox symptons at this particula juncture of this particular MC. RELAX There is nothing to figure out and you'll drive yourself nuts when there is no magic answser for all these things you are over thinking.
The SWF is the most efficient way to get the toxins out of the system as it washes the whole GI tract top to bottom. On the longer MCs more than two weeks it's a good idea to cycle off the lax tea to prevent becoming depedant. Another school of thought sez that when fasting the system responds different to the lax tea regarding becoming dependent. For me I cycle off 2 or 3 days at a time past 2 weeks and only do the SWF daily. You've been doing fine for 25 days with the SWF and you have one reaction and you're ready to throw in the towel???. Try drinking 16 oz of water when you first wake up to make sure your system is well hydrated then wait at least 30 mins before doing the SWF