You *will* have progress and setbacks on this diet, but- if you stick to it the way it is written- there will generally be an improvement in your overall condition. If it has had a positive impact for at least 4 weeks, that's a good sign there will be continued improvement.
Keep a food log. I've found that it's stomach pain (within an hour) with certain types of foods, gut pain (within 2-4 hours) after that, and for some items "fallout" begins 24-48 hours later. Work backwards from the symptoms to determine the offending component. In this case, yeah- I'd wager it's peanuts.
Interestingly, I can usually have almost unlimited quantities of peanuts for one day, but if I repeat it the second day, things get worse. So I can alternate days, or I can make it every third day, or whatever. I think it's probably due to continued growth of "bad" flora in the gut; if they're fed a single "meal" in a day, they can grow- but without being fed the second day (what with their exponential growth curve going on), there's not enough to cause problems.
Anyway. That's how I model it. It's consistent with what I know about
growing organisms on shaker tables in the lab, anyway!