Adding fiber in the diet; now massive bms, gastrointestinal pain?

Not enough water? Having an adequate amount of fiber in your diet (30 gms of soluble fiber) is important part of optimal health (helps cholesterol, regularity, etc). The large bm's is not really a problem. The pain of more concern. Most important cause is not drinking enough water, seltzer, or fruit juice with the fiber. Fiber increases gas in GI tract, could also cause pain. Exercise daily also.