Eat nothing but organic green leafy vegetables and 2 organic granny smith apples for 2-6 months depending on severity along with at least 150 billion of quality probiotics (one with 10 or more strains is ideal).
Also take 2 tbs of apple cider vinegar with 1 tspn of aluminum free baking soda 3x a day. Space probiotics and acv baking soda mix out as I think baking soda can also kill some good bacteria.
You will also need a very good multivitamin to keep you from becoming deficient. Also if I didnt have a bowel movement for 2 days or more I would take a colon cleansing supplement. Organic Spirulina is also acceptable and encouraged because it is a very good source of protein and possibly the most nutrient dense food on the planet.