Re: problem
Kegals and other exercises are all going to help, but there are two other suggestions I would make: First, make sure you're diet NOW is not contributing to the problem. You need to make sure you have plenty of raw, live food in your diet - also, make sure you're getting the nutrition you need everyday, including the right fats and minerals in your diet. Do not allow constipation to be a part of your life!
Secondly, the best way I have found to combat this problem is through using a slant board. You can buy a commercial board to use at home or you can use anything that will support your weight, which is, at least, 18 inches off the ground on one end or you can lay in the bath tub with your hips propped up on 3 or 4 folded bath towels. The idea is to get you in a head-down position so that gravity is working in your favor.
Once on the slant board, I would apply castor oil to the abdomen, then massage by placing the fingers of both hands on the pubic bone, coming straight up to the navel, then go out to the sides and back down to the pubic bone. The head-down position allows the organs to come back up where they belong, the castor oil will help to break up any old adhesions and the massage helps to pull the organs back in place while strengthening and reminding the muscles of what they're supposed to be doing. I would do this for 20 - 30 minutes every night until you begin to see improvement.
Many will tell you this is just to be expected as we age, especially after having several children, but I do not believe this is true. Just as you pointed out - we have done things which caused these problems - and, just as we caused them, we have the ability to correct them.