I would recommend kefir but since you do not have grains it would take a few days to ship/prepare it. If I were you I'd make sure I'm not getting ANY more fiber whatsoever until you next BM and drink a lot of water. What most likely happened was that heavy metals were released from the liver and stopped the digestive process. This is common. Just take vitamins and drink a lot of water and eventually you'll have a huge (and painful) BM.