The following information may help to address your question:
You can find relevant journal articles on the association between ankylosing spondylitis and Crohn's disease through a service called PubMed, a searchable database of medical literature. Information on finding an article and its title, authors, and publishing details is listed here. Some articles are available as a complete document, while information on other studies is available as a summary abstract. To obtain the full article, contact a medical/university library (or your local library for interlibrary loan), or order it online using the following link. Using "ankylosing spondylitis[ti] AND Crohn's[ti] disease" as your search term should locate articles. To narrow your search, click on the“Limits” tab under the search box and specify your criteria for locating more relevant articles. Click here to view a search.
The National Library of Medicine (NLM) Web site has a page for locating libraries in your area that can provide direct access to these journals (print or online). The Web page also describes how you can get these articles through interlibrary loan and Loansome Doc (an NLM document-ordering service). You can access this page at the following link http://nnlm.gov/members/. You can also contact the NLM toll-free at 888-346-3656 to locate libraries in your area.