Sounds like I am suffering from the same thing and I can rule out a batch issue as I haven’t ordered any new product. I started with Huel Black (salted caramel/strawberries and cream/banana). I only have one 2 scoop shake on each week day and that is either at breakfast or lunch. For 2 months no issues but then noticed in the week before Christmas - feeling flushed in my face and stomach pain which passed after digestion. Then after a break for Christmas I have started again and the reaction is worse. The facial flush is immediate followed by stomach pain and then diarrhoea. Today tried a single scoop and the symptoms were less severe but still had diarrhoea.I am afraid this is the end of my Huel journey.