Preventing constipation will be key in preventing any worsening, and allowing them to heal. Things that help prevent or treat constipation include staying adequately hydrated, and eating plenty of whole grains, fruits and veggies. Except for bananas; they will back you up. Peaches, and pears, and fruit juice are also helpful. Things that typically cause stools to be harder are meats, and cheese, as well as not drinking enough water. Women in pregnancy tend to get more constipated anyway, due to bodily changes, so we tend to have to keep a closer watch on things. If you need a little extra help, miralax (or the cheaper, equivalent off-brand,) is generally gentle, yet effective, and it's not absorbed systemically; it just passes through the digestive tract, so you don't have to worry about any side effects to the baby, like I'm so paranoid about.
For treating them, in the past I've used tucks pads, witch hazel poured onto menstrual pads, and frozen, for use postpartum, and preparation H. I know preparation H isn't very natural, but the maximum strength stuff woks pretty well. Also, get some flushable wipes, because keeping the area very well, and gently cleaned will also be very important. I can tell you right now, from being a CNA, and a nurse, toilet paper doesn't get anyone adequately cleaned from bowel movements. I think everyone should use wipes.
This time around, I'm also preparing essential oils, which I'm still pretty new to. They say making a spray where you add 20 drops each of helichrysum and lavender oil to a bottle of witch hazel, is supposed to be wonderful for a healing and pain relieving perineal spray, and especially for hemorrhoids. I'm going to try that this time around.