Painful Bowel Movements Once a Month

For the last couple of months I have been having very painful bowel movements once a month for a couple days.
It usually starts about a week and a half after my period.
It feels very dry and irritated and my stool is hard.

I know that there is a cut, too, that looks to have a skin tag and that gets more irritated with each bowel movement.

I never even knew what constipation was until I was 27....4 years ago. Before that I had always had the opposite problem, if I was not having normal BM's. And I frequently got stomach aches and I was quite thin.

Four years ago, I gained about 15 pounds and started having painful bowel problems. I would be almost bed-ridden for a couple of days because I couldn't go to the bathroom, but it felt like I had to and I hurt like knives piercing when I tried. It would return after this point, every 6 months to a year.

Then a year a half ago, I had my son by unplanned c-section and ever since then I started having this problem every 3 months until 4 months ago in August when I started having it every month. The rest of the month, I usually feel not quite normal, but it is very bearable. I eat 30-35 g of fiber a day for the last month or so. Yesterday, the problem started again, though. It is quite miserable, but I can't go to the doctor until my insurance kicks in on Jan. 1, 2010. Then I can at least begin the whole doctor process.

I think it could be hypothyroidism. But suppose it could also be a vitamin deficiency or bacterial overgrowth or adhesions from the c-section. Also, I have read about lichen sclerosus, too. Or hormonal, since it seems to be on a schedule every month now.

Sometimes I wish Dr. House was real!