Here are some more links regarding oral contraceptives. . Sorry they're so long.
http://linkinghub.elsevier.com/retrieve/pii/S0016508598704196
http://www.ingentaconnect.com/content/bsc/ajg/2008/00000103/00000009/art00036
http://www3.interscience.wiley.com/journal/120084927/abstract
http://books.google.com/books?id=mc5xDyUtNAQC&pg=PT148&dq=ibd+oral+contraceptives&lr=
http://books.google.com/books?id=2DPXoBJC_CoC&pg=PA201&dq=ibd+oral+contraceptives+date:2007-2009&lr=&as_brr=0&as_pt=ALLTYPES
There seems to be a connection with Crohn's pain and oral contraceptives, so the same might hold true with estrogen replacement.
http://www.crohns.org.uk/Docs/5/The%20oral%20contraceptive%20pill%20and%20Inflammatory%20Bowel%20Disease.html