I have had excellent flush results without Epsom Salts or any other substitutes.
As long as you dissolve the stones and make sure to clean out your digestive tract on the day after the flush with a Salt Water Flush, or enema, or colonic, or P&B shakes and a laxative, you really don't need those pesky Epsom Salts . And it makes the flush a much more pleasant experience too! :)
If the bleeding was due to skin irritation, you may want to look into changing your diet so your skin is healthier and stronger, able to handle the corrosive effect of bile and salts. Drinking Aloe Vera juice helps! And man, you GOTTA use Charmin! ;)