A crosslinked cation exchange polymer for use in removing potassium from the gastrointestinal (GI) tract of an animal subject in need thereof wherein less than 25% of subjects taking the polymer or composition once per day experience mild or moderate GI adverse events. The preferred polymer to be crosslinked is poly(α-fluoroacrylic acid) in salt form. The preferred crosslinking agent is divinylbenzene (DVB). The crosslinked cation exchange polymers have beneficial physical properties, including combinations of particle size, particle shape, particle size distribution, viscosity, yield stress, compressibility, surface morphology, and/or swelling ratio. The polymers may be formulated into pharmaceutical compositions, such as with a linear polyol, especially sorbitol and/or xylitol. These polymers and/or compositions bind to potassium in the GI tract, and are thus are particularly useful for the treatment of hyperkalemia.
