Baseline characteristics (intention-to-treat population)
| Azathioprine (n=41) | Mesalazine (n=37) | |
| Age (years), mean±SD | 35.5±13.6 | 36.0±10.7 |
| Male gender, N (%) | 24 (58.5%) | 20 (54.1%) |
| Body mass index (kg/m2), mean±SD | 23.8±4.0 | 23.2±3.1 |
| Smoker, N (%) | 17 (41.5%) | 20 (54.1%) |
| Course of Crohn's disease, N (%) | ||
| Continuous | 21 (51.2%) | 20 (54.1%) |
| Recurrent | 19 (46.3%) | 17 (45.9%) |
| Unknown | 1 (2.4%) | 0 |
| Behaviour of Crohn's disease, N (%) | ||
| Non-stricturing/non-penetrating | 4 (9.8%) | 6 (16.2%) |
| Stricturing | 10 (24.4%) | 15 (40.5%) |
| Penetrating | 27 (65.9%) | 16 (43.2%) |
| Baseline CDAI | ||
| Mean±SD | 70±44.9 | 102±61.8 |
| Median (range) | 72 (−29 to 209) | 93 (−10 to 204) |
| Screening CDEIS, mean±SD | 5.5±3.46 | 4.9±3.01 |
| Screening Rutgeerts score, mean±SD | 3.17±0.89 | 2.97±0.93 |
| No. (%) of patients with screening Rutgeerts score: | ||
| >5 aphthous lesions (i2a) | 12 (29.3%) | 16 (43.2%) |
| Lesions confined to the ileocolonic anastomosis (i2b) | 1 (2.4%) | 0 |
| Diffuse aphthous ileitis with diffusely inflamed mucosa (i3) | 8 (19.5%) | 6 (16.2%) |
| Diffuse inflammation with already larger ulcers (i4) | 20 (48.8%) | 15 (40.5%) |
| Baseline IBDQ, mean±SD | 191.2±27.12 | 175.2±32.39 |
| Time since last bowel resection (months), median (range) | 13.5 (6.3–26.1) | 12.5 (5.8–19.8) |
| Treatment prior to surgery, N (%) | ||
| Mesalazine | 28 (68.3%) | 26 (70.3%) |
| Sulfasalazine | 4 (9.8%) | 1 (2.7%) |
| Budesonide | 9 (22.0%) | 13 (35.1%) |
| Corticosteroids | 23 (56.1%) | 16 (43.2%) |
| Azathioprine | 6 (14.6%) | 8 (21.6%) |
| Infliximab | 2 (4.9%) | 1 (2.7%) |
| Other | 6 (14.6%) | 6 (16.2%) |
| Mesalazine treatment within 2 weeks prior to study entry, N (%) | 15 (36.6%) | 12 (32.4%) |
| Symptomatic treatment for diarrhoea within 2 weeks prior to study entry, N (%) | 1 (2.4%) | 1 (2.7%) |
| Concomitant medication, N (%) | ||
| NSAIDs | 12 (29.3%) | 10 (27.0%) |
| Cumulative intake of ≤7 days | 9 (22.0%) | 5 (13.5%) |
| Cumulative intake of >7 days | 3 (7.3%) | 5 (13.5%) |
| Aspirin and analgesics without anti-inflammatory effect | 17 (41.5%) | 20 (54.1%) |
| Medication for functional gastrointestinal disorders | 9 (22.0%) | 8 (21.6%) |
CDAI, Crohn's disease activity index; CDEIS, Crohn's Endoscopic Index of Severity; IBDQ; Inflammatory Bowel Disease Questionnaire; NSAID, non-steroidal anti-inflammatory disease.