33 RCTs were used to assess the role of rectal corticosteroids ( N = 2406 patients).
2 RCTs were used to compare rectal corticosteroids and placebo (N = 58 patients).
2 RCTs were used to compare rectal budesonide and placebo (N = 274 patients).
2 RCTs were used to compare rectal and oral corticosteroids (N = 96 patients).
7 RCTs were used to compare rectal corticosteroids and rectal 5 - ASA (N = 682 patients).
2 RCTs were used to compare rectal corticosteroids and rectal 4 - ASA (N = 85 patients).
5 RCTs were used to compare rectal corticosteroids and rectal budesonide (N = 463 patients).
3 RCTs were used to compare mean cortisol concentrations after 4 weeks of treatment with rectal budesonide compared to conventional rectal corticosteroids (N = 224 patients).
Median validity score (out of 30) was 21 (range 9 to 26). Adverse effects were inconsistently reported.
Conventional rectal corticosteroids (hydrocortisone, prednisolone, betamethasone): improvement rates: symptomatic 77%, endoscopic 66%, histological 52%; remission rates: symptomatic 45%, endoscopic 34%, histological 30%.
Topically active corticosteroids (budesonide, beclomethasone, prednisolone meta sulphobenzoate): improvement rates: symptomatic 73%, endoscopic 69%,histological 55%; remission rates: symptomatic 46%, endoscopic 31%, histological 23%.
Aminosalicylates (5 - ASA or 4 - ASA):improvement rates: symptomatic 81%, endoscopic 75%, histological 65%; remission rates: symptomatic 52%, endoscopic 39%, histological 32%.
Placebo: improvement rates: symptomatic 34%, endoscopic 38%; remission rates: symptomatic 9%, endoscopic 17%.
Rectal corticosteroids and placebo: improvement: symptomatic OR = 0.21 (95%CI: 0.07, 0.71), endoscopic OR = 0.27 (95%CI: 0. 10, 0.77); remission: symptomatic OR = 0.07 (95%CI: 0.02, 0.29), endoscopic OR = 0.34 (95%CI: 0.10, 1.20).
Rectal and oral corticosteroids: could not be pooled due to substantial differences in oral dose.
Rectal corticosteroids and rectal 5 - ASA: improvement: symptomatic OR = 1.36 (95%CI: 0.88, 2.09), endoscopic OR = 1.06 (95%CI: 0.61, 1.85), histological OR = 2.27 (95%CI: 1.22, 4.27); remission: symptomatic OR = 2.42 (95%CI: 1.72, 3.41), endoscopic OR = 1.89 (95%CI: 1.29, 2.76), histological OR = 2.03 (95%CI: 1.28, 3.20).
Analysis repeated after excluding a trial with larger volume of 5 -ASA and after excluding trials using foam preparations : 5 - ASA remained superior (no results given).
Rectal corticosteroids and rectal 4 - ASA: improvement: symptomatic OR = 3.88 (95%CI: 1.29, 11.64).
Rectal corticosteroids and rectal budesonide: improvement: symptomatic OR = 2.08 (95%CI: 0.84, 5.14), endoscopic OR = 1.40 (95%CI: 0.87, 2.25), histological OR = 1.23 (95%CI: 0.80, 1.91); remission: symptomatic OR = 0.85 (95%CI: 0.44, 1.63), endoscopic OR = 1.14 (95%CI: 0.69, 1.88), histological OR = 0.68(95%CI: 0.28. 1.67).
Rectal budesonide and rectal 5 - ASA: endoscopic OR = 0.58 (95%CI: 0.27, 1.22); remission: one OR and CI reported but it is not clear which outcome is referred to.
Mean cortisol concentrations after 4 weeks of treatment with rectal budesonide compared to conventional rectal corticosteroids: weighted mean difference between pooled treatment arms = 119.1 nmol/l (95%CI: 70.3, 167.9).