Pain with tight clothes and & IBS

Hello everyone.I have been suffering from digestive symptoms for more than a year. Started with excessive gas, diarrhea, burping and abdominal pain. I had all types of investigations : blood tests, stool tests, CT, MRI, gastroscopy and colonoscopy and endoscopic ultrasound, all came back clear. I was given the diagnosis of IBS. Tried low FODMAP diet for a short period of time but it didn't help and gave me constipation. My symptoms improved a bit with exercising and reducing food intake (as I was attempting weight loss). I stopped exercising more than a month. Now I have all my symptoms back in addition to severe cramping/squeezing abdominal pain whenever I wear tight clothes. Even the normal bra strap causes severe pain in the region.I can't wear a bra anymore at home. Pain goes away or gets better when I remove the tight clothing. I don't know if this could be related to IBS or something else and if there is something that helps with this symptom.