What can I take to help me poo that is safe having an auto immune illness and irregular heart beat?

All Bran. High fiber cereals work beautifully, are safe, cheap, and don't require a prescription. All bran, fiber one, raisin bran are examples - read the label: look for "fiber" - you want to eat cereals that have >6 g /serving (fiber one is 14!). Try to eat a minimum of 10-20 grams a day. If it doesn't work, up it to 30 g. If you get too much gas, reduce it.