Other hemolytic anemias to be considered include G6PD deficiency, especially in patients considered for sulfasalazine therapy. The latter is believed to be marker of monocyte activation, particularly in Crohn s disease with procoagulant formation. Arterial thromboses are unusual, but digital gangrene has been reported with a contributing role of cryoglobulinemia or cryofibrinogenemia. These presentations include small bowel obstruction of abrupt onset often due to acute inflammation as well as stricture. Fistulous disease to the perineum with recurrent intractable perianal abscesses or the vulvovaginal area may masquerade as a refractory draining Barthoin s cyst or abscess.
Enterocutaneous fistulae seem to favor the umbilicus or prior surgical incisional sites.
Retroperitoneal fistulae may present with psoas abscess or chronic osteomyelitis from fistulae to sacrum. Enterovesical and enteroenteric fistulae have been discussed above. With attention directed to the underlying bowel disease, the clinician s awareness of the varied presentations of IBD will save immeasurable time, expense, and anxiety.