Any tips to manage Abdominal pain & Joint pain from HSP

Thank you all so much for the replies/suggestions. We have now started her on ranitidine as we suspect that the tummy pain could be due to heartburn and this seems to help. The interesting thing was that her tummy pain was increasing at times when she was having food (probably excess stomach acid). I have also temporarily stopped all supplements I was giving her like vitamin C, vitamin D, L-glutamine etc to check whether these are irritating her stomach. This was interesting as the pain she has felt from heartburn before the HSP had been very mild. I'm now wondering whether the painkillers she has taken for tummy pain in the past 2 months has caused this heartburn. My daughter had a kidney infection from the HSP and though she was not on steroids, she had taken acetominophen many times for pain relief over the last 2 months for the stomach pain/joint pain per the recommendation from her nephrologist and pediatrician (we have kept her off ibupruffen due to the kidney infection). I'm wondering whether the painkillers killed off some good bacteria in her gut over the period.

Thanks again for the suggestions - I have started my daughter on ranitidine and will introduce probiotics after monitoring her condition for a few days. Also for whoever it might help, my daughter had a few acupuncture sessions and that significantly helped reduce her joint pain in her knees/ankles and stomach pain due to stomach cramps (not the latest one due to the heartburn).