Bechet's colitis: a differential diagnosis in inflammations of the large intestine

A previously well 39 year old woman presented with severe localized and painful anorectal ulceration. There were no other associated symptoms apart from arthritis of the hips and fingers. In the absence of definitive tissue diagnosis, a presumptive diagnosis of Crohn's disease was made. After a period of progression, the inflammation and ulceration subsided with conservative therapy. Following a relatively symptom-free period of 7 years, painful ulceration recurred in the same segment of bowel, which was refractory to steroid therapy but responded to defunctioning of the rectum. Upon excision of the defunctioned rectum, multiple discrete ulcers developed in the remaining colon, with a fistula from the distal sigmoid colon to the midline wound. The patient simultaneously developed painful apthous ulceration of the mouth and throat, and pustules appeared on the perianal skin and trunk for the first time. A colectomy was performed, with good results. The pathology of the colonic lesions is described. The characteristic appearance of these lesions, together with associated 'major' and 'minor' clinical criteria, enabled a diagnosis of Bechet's disease to be made. Although there is some overlap, particularly in the distribution of this condition with Crohn's colitis, the pathologic appearances in Bechet's colitis are relatively distinct. A diagnosis of Bechet's colitis should not be excluded in a patient presenting with atypical inflammatory bowel disease, even if associated clinical criteria are not simultaneously present.