The investigators demonstrated that cholestyramine is an effective binding agent in vitro for
porphyrins. A few isolated case reports of treatment of individuals with a cutaneous
porphyria suggest that cholestyramine and colestipol effectively remove porphyrins.
Hypothesis: orally administered colestipol will effectively reduce sun sensitivity and lower
erythrocyte porphyrin concentrations in subjects with erythropoietic protoporphyria (EPP).