cytomegalovirus ( cmv ) colitis is common among immunocompromised patients who are more prone to opportunistic infections . after the infection of cmv is detected by histology or serology , antiviral treatment is usually chosen initially . since cmv disease can not be diagnosed on clinical symptoms alone , diagnosis and treatment are sometimes delayed . here , we report a case of a hemorrhagic cmv colitis that occurred in an immunocompromised patient after a colectomy due to colon cancer and was successfully treated with ganciclovir . an 85-year - old woman underwent esophagogastroduodenoscopy and colonoscopy for investigation of anemia . a laterally spreading tumor of the granular type , 85 mm in diameter , although magnifying image - enhanced colonoscopy suggested a tubulovillous adenoma , surgical resection , not endoscopic mucosal resection , was chosen because of the size of the tumor . however , as she had a medical history including breast cancer , myocardial infarction , general edema due to chronic renal failure ( oral administration of prednisolone 5 mg / day ) , diverticulosis of sigmoid colon , and bilateral ureteral stent placement due to retroperitoneal fibrosis , she did not want to take medical treatment anymore but to monitor her own condition for a while . after 3 months , she finally agreed to have surgery and was admitted to our hospital . the patient underwent ileocecal resection followed by stapled functional end - to - end anastomosis ( fig . the postoperative course was favorable ; dietary intake and oral drug administration were started on postoperative day 4 and both flatus and stool passed . however , she had sudden abdominal pain and heavy bloody discharge on postoperative day 11 . although conservative treatment , including blood transfusion therapy for anemia , was performed initially , there was no improvement after a week . in addition to the endoscopic findings , the patent 's immunocompromised state suggested possible cmv colitis . because cmv antigen was confirmed in peripheral blood samples , intravenous antiviral treatment was started from the postoperative day 23 ( ganciclovir , 150 mg / day ) . after 4 days of the treatment , bloody discharge stopped , and at 8 days , improvement of abdominal pain was observed . the antiviral treatment was continued for 2 weeks until the serological confirmation of negative cmv antigen . after improvement of the colitis - related symptoms , the patient was discharged from our hospital . cmv infection often develops a latent infection with no signs or symptoms after acute infection . although most people are exposed to cmv in their lifetime , typically only the patients with weakened immune systems , such as aids , malignancy , organ transplant or bone marrow transplant , and steroid or immunosuppressive treatments , become ill by reactivating cmv and present with cmv pneumonia , gastroenteritis , retinitis , and encephalitis . cmv disease is often diagnosed by pathologic and serologic confirmation because clinical symptoms are not specific . furthermore , colonoscopic findings of cmv colitis mimic many conditions , including pseudomembranous colitis , ischemic colitis , ulcerative colitis and crohn 's disease . in our case , as we initially considered the bleeding from the diverticulum or anastomosis , conservative treatment was chosen . after one week of conservative therapy , there was no sign of improvement in bloody discharge ; therefore , we decided to perform colonoscopy . we were hesitant to perform colonoscopy due to our patient having had a colectomy . according to the meta - analysis of cmv colitis in immunocompetent hosts , the highest mortality rates were associated with immune modulating conditions that include 16 patients . of those analyzed , 5 patients ( 31.3% ) received colectomy as initial treatment and 8 patients ( 50% ) and 6 patients ( 37.5% ) had coexisting renal failure and diabetes mellitus , respectively . in our case , as the patient was given steroids due to chronic renal failure and the colonoscopy revealed the longitudinal ulcer at the anastomosis , we were able to suspect cmv colitis and confirmed the diagnosis serologically . because endoscopic biopsy was not performed , cmv infection was not evaluated histologically . of note , we performed immunohistochemistry of cmv protein using resected colon cancer specimen , though cmv - positive stain was not detected . this result seems to relate with the fact that cmv is not associated with carcinogenesis and reactivation of latent cmv infection causes cmv colitis [ 5 , 6 ] . the first choice of treatment of cmv infection is antiviral therapy [ 7 , 8 ] . systemic antiviral treatment has provided significant advances and has resulted in dramatically improved outcomes [ 7 , 8 ] . treatment time usually ranges from 1 to 4 weeks , depending on the treatment effect such as improvement of the symptoms and/or confirmation of the negative cmv antigen . in our case , despite the necessity of reducing the dose of ganciclovir due to renal failure , the patient showed good response to systemic therapy and did not require further treatment . fortunately , as she did not show uncontrollable heavy bleeding or symptoms of bowel perforation , surgical resection was not needed . the case we mentioned above can potentially occur in immunocompromised patients . with recent progress in medicine , the number of high - risk patients who undergo surgery is increasing ; therefore , the reactivation of latent cmv infection in immunocompromised patients should be actively considered for the differential diagnosis , leading to timely diagnosis and appropriate treatment .
we report a case of hemorrhagic cytomegalovirus ( cmv ) colitis , occurring in a postoperative patient due to a weakened immune system . 
 an 85-year - old woman with a medical history , including chronic renal failure treated with oral administration of prednisolone , underwent colectomy due to an ascending colon cancer . while the postoperative course was favorable , she exhibited acute severe abdominal pain and massive bloody discharge after 11 days of surgery . 
 her colonoscopic examination showed multiple longitudinal ulcers on the anastomosis . 
 in addition to these endoscopic findings , her past medical history helped suggest cmv colitis . because serological testing revealed positive cmv antigen , she was finally given a diagnosis of cmv colitis and received intravenous ganciclovir for the initial treatment . 
 hemorrhagic cmv colitis after colectomy is an important postoperative complication ; we therefore present our case with diagnosis and treatment experience .