Boku Super Fiber is Dr. formulated to be gentle and effective without the use of toxic herbs or cheap fillers of any kind. That said, every-body is different. Depending on a variety of factors, you could possibly experience constipation, diarrhea, cramping and other symptoms. You must remember to drink plenty of water and be sure to consult your physician if these or other reactions occur. The most desired and probable reaction is a bowel movement.