Analysis 2.4. Comparison 2 Probiotics versus 5-aminosalicylic acid (5-ASA) (mesalazine), Outcome 4 Minor adverse events........ Analysis 2.5. Comparison 2 Probiotics versus 5-aminosalicylic acid (5-ASA) (mesalazine), Outcome 5 Serious adverse events...... Analysis 2.6. Comparison 2 Probiotics versus 5-aminosalicylic acid (5-ASA) (mesalazine), Outcome 6 Withdrawal due to adverse events.