I can share my experiences with everyone because they have been horrific but now I am on a regime that works. I have suffered with gastro issues the whole bloody pregnancy and had 2 emergency enemas at abour 22 weeks. I am now on a regime that works that was worked out by my OB and a gastroenterologisy so I feel confident that this is not only a great regime more generally but it safe in pregnancy
First, medication. Clearly if you are as blocked up as I was and y'all seem to be a little bit blocked (poor angels, I feel your pain, I do!), you need more than just dietary control. Diet is imperative, but alone won't solve the issue if its bad. For the US ladies, the gastro peeps recommend Miralax - its a non-dependent laxative (i.e your body won't get used to it and rely on it to go when your pregnancy is over) that is safe in pregnancy. I take it twice a day, but the gastro dude said I can modify the dose up or down depending on my reaction. I disolve it in a glass of prune juice and suck it down. In addition, I take 4 colase (a stool softener) a day - this is probably more than most of you want to take, in fact for most people the miralax will be enough, but the combination of the miralax and colase is what keeps things going for me.
A warning about peri-colase, dulcolax and other laxatives including suppositories (I saw one of you mention supps and one peri-colase). These are all creating system-based reliance, meaning your body is getting used ot them helping it out and it will be harder to go when you stop taking them after the pregnancy is over. In addition, my gastro tells me (and this happened to me) that these laxatives, esp the supps can cause more problems particularly inflaming and irratiating the gastric system - I ended up with colitis (inflamation of the colon) because I was trying to solve the problem with supps.
Second, food. Some food acts as binders, regardless of its wholegrain nature etc. Foods to avoid according to the gastro: potato (boooo), rice, bread, pasta. I eat a little bit of toast (like 2 slices) every second day and sometimes some potato, but I have noticed an effect when I do. Foods to eat that I have found helpful: beans - I make "poo salad" with a tin of cannelli beans, a tin of sweet corn, some chopped celery, parsely, salt, oil, and white wine vinegar - it has an impact, hence the name

Flax seeds are also awesome as someone else mentioned - you want to grind them enough that the outer shell breaks, but not grind them to a powder. Fruits etc are also great.
Hope this helps someone - I feel your pain
Z
xx