I just switched from Nlarge to Heavyweight gainer 900 and man these last couple of days my stomach has gone to ****. All I did this whole week was **** water and cause my ass to irritate. Horrible experience I dunno why. Has this happened to any of you? I went back to Nlarge today and took a crap and had no problem. Just like any old ordinary day. Anyone else have this problem? Is the shake the cause or could it be another problem?