ABSTRACT
<p><b>BACKGROUND</b>Gastrointestinal graft versus host disease (GI-GVHD) and cytomegalovirus (CMV) enteritis are important complications following allogeneic haematopoietic stem cell transplantation (allo-HSCT). We explored the role of colonoscopy in the diagnosis of GI-GVHD and CMV enteritis following allo-HSCT to identify the endoscopic manifestations of GI-GVHD and CMV enteritis was made.</p><p><b>METHODS</b>A retrospective analysis of the colonoscopic manifestations of GI-GVHD, CMV enteritis and GI-GVHD with concurrent CMV enteritis (GconC) and their related clinical issues.</p><p><b>RESULTS</b>Forty-seven patients underwent 50 colonoscopies with diagnoses of 32 GI-GVHD, 7 CMV enteritis and 11 GconC. Both GI-GVHD and CMV enteritis had colonic mucosal lesions with various manifestations under colonoscopy. Tortoise shell like changes of the mucosa (12 of 32) and deep ulcers (2 of 7) were specific endoscopic manifestations for GI-GVHD and CMV enteritis, respectively, while mucosal oedema, erythema, congestion, erosion and shallow ulcers could not be used to differentiate GI-GVHD from CMV enteritis. GconC patients were prone to have oozing bleeding of the end ileal mucosa and typhlodicliditis. Of the biopsed specimens for GI-GVHD, CMV enteritis and GconC, 64%, 70% and 44% were taken from the rectum and sigmoid colon respectively.</p><p><b>CONCLUSIONS</b>Following allo-HSCT, tortoise shell like changes and deep ulcers of the colonic mucosa are characteristic changes for GI-GVHD and CMV enteritis, respectively, while the other lesions are not. Most of the GI-GVHDs and CMV enteritis cases can be diagnosed by left colon examination and tissue biopsy, but total colon examination to the terminal ileum is preferred.</p>