Vedolizumab showed no clear difference in serious adverse events compared with placebo (moderate certainty).
It is very uncertain whether parenteral iron changes serious adverse events compared with inactive control (very low certainty).
It is very uncertain whether oral iron changes serious adverse events compared with inactive control (very low certainty).
It is very uncertain whether terlipressin changes non‐serious adverse events: diarrhoea or abdominal pain, or both compared with other vasoactive drugs (very low certainty).
Berotralstat showed no clear difference in serious adverse events (during compared with placebo or active control (low certainty).
It is very uncertain whether C1 esterase inhibitor changes serious adverse events (during compared with placebo or active control (very low certainty).
It is very uncertain whether plasma‐derived C1 esterase inhibitor changes serious adverse events (during compared with placebo or active control (very low certainty).
The review found no eligible studies for this question.
It is very uncertain whether recombinant human C1 esterase inhibitor changes serious adverse events (during compared with placebo or active control (very low certainty).
Lanadelumab showed no clear difference in serious adverse events (during compared with placebo or active control (low certainty).
It is very uncertain whether infliximab changes serious adverse events (at 56 weeks) compared with adalimumab (very low certainty).
Two infusions of natalizumab (300 mg or 3 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).
Two infusions of natalizumab (6 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).
Three infusions of natalizumab (300 mg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).
Three infusions of natalizumab (300 mg) and two infusions of… showed no clear difference in serious adverse events up to week 10 compared with placebo and two infusions of infliximab (low certainty).
One infusion of natalizumab (300 mg or 3 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).
Belimumab 10 mg/kg showed no clear difference in participants with one or more serious adverse events compared with placebo (low certainty).
It is very uncertain whether fecal microbiota transplantation changes serious adverse events with use of FMT for induction of remission in… compared with control (very low certainty).