Int Urogynecol J (2011) 22:477–483 antibiotics were not given routinely. After removal of the catheter, urine samples were taken for sedimentation and culture. Patients with complaints and sedimentation show- ing signs of urinary tract infection were given antibiotics. Signs of urine tract infection were defined as having more than 25 white blood cells per high power field, nitrate production, or more than 20 bacteria per high power field. When urinary tract infection after the removal of the catheter was confirmed by a positive culture, patients were treated with antibiotics irrespective of complaints. A culture was scored positive when the sample contained more than 105 colony forming units per milliliter. For the outcome measure urinary tract infection, only the infections proven by a positive culture at the time of the first removal of the catheter were included. No other urinary cultures were taken on behalf of the study protocol. All patients were given the opportunity to leave the hospital on the third day postoperatively. For patients in the 5-day protocol who requested to leave the hospital with an indwelling catheter in situ, an appointment was made on the fifth day in the outpatient clinic for ultrasound 6–8 h after removal of the catheter by themselves at home. The primary outcome measure in the study was the number of patients with temporary catheter replacements after removal of the first indwelling catheter postoperative- ly. Based on retrospectively collected data in one of the participating hospitals, the average percentage of patients needing repeated catheterization after removal of the catheter on the fifth day after an anterior colporrhaphy was 10%. To show a difference of at least 15% in the number of repeated catheterizations between a protocol of 2 versus 5 days, with a significance of 0.05 and a power of 90%, it was calculated that 112 patients in each group were needed. The study was started with the intention to include 224 patients. After 2 years of inclusion, an amendment to the study was made to perform long-term follow-up 2 years postoperatively. Therefore, the intended inclusion was increased to 250 patients, taking into account a loss to long-term follow-up of 20%. All data were collected and analyzed in SPSS 15.0 for Windows. The t test, Pearson chi-square test, Fisher’s exact test, and univariable and multivariable logistic regression were used in the statistical analysis of all data. All patients were analyzed according to the intention to treat principle. Results Between January 2006 and September 2008, 390 patients underwent an anterior colporrhaphy. Figure 1 shows the patient flow of the study. Two hundred fifty out of 390 479 patients (64%) agreed to be included in the study. Three patients withdrew from the study just before the operation. One patient did not undergo the planned operation because under general anesthesia a tumor in the rectum was palpated and treatment was taken over by the surgeon. Two hundred forty-six patients were randomized after the operation. One patient, randomized to the 2-day protocol, died of a heart attack on the first postoperative day with the catheter in situ. She died before she could participate in the study. Two patients allocated to the 5-day protocol had their catheter removed on the third day because of miscommunication. The three patients were analyzed in the allocated group. In 20% of patients, the protocol was not followed and a culture of the urine was not obtained after removal of the catheter. Follow-up after 6 weeks was achieved in 245 patients. Patient characteristics in both groups are shown in Table 1. There were no significant differences between both groups with respect to age, BMI, Baden–Walker classification of cystocele and rectocele, history of symptoms, history of surgery, pre-operative urine tract infections, concomitant surgery, mean amount of blood loss and use of levator sutures, or tobacco plication of the bladder. However, more patients had undergone Kelly sutures in the 5-day protocol group than in the 2-day protocol group. Table 2 shows the outcome measures of the two groups. Twenty-eight percent of patients in the 2-day protocol needed temporary catheter replacement compared to 9% of patients in the 5-day protocol (p <0.01). In 196 patients, urine was sent for culture after removal of the catheter. After 2 days, significantly less patients had urinary tract infections, proven by a culture with >105 colony forming units per milliliter, than after 5 days of catheterization (22% versus 37%, p = 0.02). Of all patients, 67% had an uneventful postoperative period, defined as having no post-voiding residual volume more than 200 mL and having no urinary tract infection at time of the first catheter removal. There was no difference between the two protocols in number of patients with an uneventful postoperative period (67% versus 66%, p = 0.86). The median duration of hospital stay was shorter in the 2-day protocol group, compared to the 5-day protocol group (median 3 versus 5 days). To prevent one temporary indwelling catheter replacement, six patients should have their catheter left in place for 5 days instead of 2 days. Giving a patient a catheter for 5 days instead of 2 days lengthened the hospital stay by 2 days. Table 3 shows the association between the two outcome measures: urinary tract infections and temporary catheter replacement. In the whole study population, a urinary tract infection at time of first catheter removal was associated with a post-voiding residual of more than