I have the same problem. For me, it's because my insides all fell when I was in my early 20's. Everything is squished together in such a way it's like having a small impaction. Any time I've needed to prepare for a medical test or childbirth etc.. I needed an entire box of laxatives to get cleaned out. I don't do laxatives though. I don't want to make my problem even worse.
I've learned the fiber pills are USELESS. I have compared all of them and figured out how much they cost per gram of fiber and it's shocking how much these stupid companies are ripping people off. I can get more fiber than that with food any day of the week.
The fiber is important. BUT, we have to drink enough water a long with the fiber to make it move. We also have to do it on a consistent basis. To even come close to a normal life I have to do around 75 grams of fiber per day. That's 3 times what they say is needed by the average person.
Quaker Oats makes a high fiber cereal with 10 grams per serving. Also there is a fiber bar that has 9 or 10 per bar depending on which flavor. I eat at least 2-3 bars per day and the hot oatmeal. These are low enough in calories not to send me over my daily calories and I've lost quite consistently for the last 3 months even consuming this much bread/cereal products.
Another thing that helps me is walking. I don't get the chance to do it enough and I get so bored. But if I walk 5 miles in a day I will get diarrhea in a couple days or maybe even after the first day. It isn't the kind that would make me sick or anything. It just ends any current constipation I have in the most comfortable way possible. If I don't eat right and get enough exercise and drink enough water, my body will create a very painful all night attack that will clean me out and that's anything but comfortable in addition to robbing me of sleep.
I also eat a lot of healthy choice boxed dinners. They have a nice variety and a healthy amount of fiber and a low amount of salt. I rarely eat the things my family eat these days. There are also some pasta companies that have started putting a nice amount of fiber in as well. It's shameful to compare how much fiber has been added to all these products and without raising the prices so much. But if you compare the total milligrams of fiber in the fiber pills and how much that costs you will be ANGRY!
I also do try and do activia yogurt sometimes but it is expensive and I don't really see that it helps all that much. These days more and more companies are adding pro-biotics to juices and products of all kinds. So I notice that and eat it when I can.
I don't think I'll ever be right. My doctor recently told me that he doesn't think I'll avoid surgery forever. BUT...they told me that when I was in my 20's and I've kept from having to do it for 20 years so far.
Suzi