Cascara Sagrada is very bitter herb and can overstimulate the liver. Senna tea with a little vitamin C should be a little more gentle on the liver. Sounds like your liver/GB might be overstimulated. You might have to go on a water/veggie juice fast for a few days to calm the storm.
I know what your going through. When I lost my flora in my colon I became completely constipated and get colonics done to flush out mucus and fecal matter. Laxatives can be a pain due to the cramping and dehydration they can cause.