Pain/Discomfort Left Side Abdomin(abdomen) at Belly Button Level near Menstrual Cycle

I have been experiencing constipation/bloating/discomfort to the left of the belly button on the left side pre and post menstrual period. The discomfort comes on a few days before my period, worsens on the day right before my period and feels like I have an intestinal blockage to the point of causing nausea. After my period it worsens as well for the duration of spotting that usually occurs up to 3-4 days after my period is supposed to end (or in other words 1 week after it began.) For the past 3 years I have not been able to completely empty my bowels when I go to use the restroom. About 2.5 years ago my Gynecologist performed an ultrasound on me to check for ovarian cysts but she said everything looked fine, nothing abnormal. I have tried to do some research online and some point to a small intestinal blockage if the discomfort occurs near the belly button, which is what I have. My question is why does this become so pronounced before and after my monthly cycle? Can intestinal problems be caused by the uterus? Could there be some type of swelling in the left ovary that is perhaps pushing on the small intestines which causes me pain and discomfort on the left side near the belly button? I also experience bloating and gas. I exercise 5 times a week, try to eat plenty of fruits and vegetables, eat small portions at meal times, can work on eating slower, and I really try not to eat too much fatty foods, only limiting these foods to desserts which I have about once a day. I have read that drinks like coffee can irritate IBS and I have noticed only a slight improvement when I stop drinking coffee. But then again my question is would IBS get worse with the menstrual cycle? I would greatly appreciate it if someone could give their thoughts on this matter. Thank you.

[lizzy100]

i doubt you have an intestinal blockage because you'd know about it if you did have. it sounds like the pain is just related to you menstrual cycle ie uterus pain.
the uterus wouldnt cause intestinal probs and IBS isnt affected by your cycle. it could be menstrual pain and IBS= constipation, bloating and gas.
id cut out the desert! maybe have brown toast instead for super for fibre.