I am anemic so am prescribed iron pills. The trouble is they give me constipation. My gp was asked to change to a different pill but are mucking about and not doing it. I switched the radio on last night and there was a discussion on Inside Health (I think). They said there is no scientific basis to the two pills a day default but you have less side effects and better iron absorption if you have one pill every other day. So I shall do that.