Thank you very much for your message.
I realise that an SWF, of the correct salt concentration, can be a very effective remedy for constipation. What concerns me is that the importance of the need for a correct salt concentration and the potential dangers of an incorrect one is not stressed here. For example, I've heard of people using 2 table spoons, rather than two teaspoons and that can only be dangerous. (Ask Shelley if you dont want to believe me.)
Your sister should not have worried about seeing a doctor in Europe for financial reasons. The current cost of a doctor's consultation in France, for example, is about $14 regardless of how long the consultation takes.