Cramping can result from the process of dialysis as it relates to the rapid removal of fluid from the individual by the dialysis process. The cause of cramping is more closely related to hypervolemia or fluid excess/overload. When fluid overload occurs, the dialysis machine is programmed to remove the excess fluid in the prescribed time, usually four hours. The amount of fluid overload is largely based on your "dry weight" as assessed by your physician/provider. The greater the amount of fluid gain in excess of the "dry weight" the faster the machine is required to remove the fluid to help prevent complications such as congestive heart failure or pulmonary edema.
Therefore, it is more important to focus on reducing the amount of fluid gain between dialysis treatments than the dialysis process itself. Reductions in fluid gain between treatments will go far in reducing cramping during treatments.