Hi. I also started to have some problems like you do. In september, I started to have real bad constipation - something completelly unusual and that annoys me more than anything else. I can lose sleep, be tired, have a flue, etc, but I still function. This makes me malfunction. :s
i went to the doctor and:
1. I fould out I have hemmroids - so I started taking the pills he prescribed me.
2. The constipation didn't go away; so I went to another doctor. This one prescribed me a laxative and a digestion regularizer, called laevolac (it's only one syrup). I had it as she told me to and the constipation went away.
3. To get my intestines to work properly, besides taking the lax, she told me to improve my diet: rich in fibers - whole cereal, fruits (kiwis and oranges are the best), vegetables (soup and salads are a must have!), drinking a lot of water. I already had this kind of diet, but she told me to see if I could improve it.
4. Some time later, I got constipated again, but only for a few days. Had more kiwis than usual and they helped.
5. I also started to eat yogurts with bifidus, because they helps the digestion.

hope this works!