IBS or IBD

I was diagnosed with IBS about 15yrs ago.  I managed symptoms with diet.  About 6 months ago I stopped smoking.  I began having a multitude of symptoms I blamed on perimenopause, but after a trip to my OB/GYN and an ultrasound revealing only endometrial polyps, she blames the rest on gastrointestinal issues.  Primary care Doc said he thinks it's Crohns, but I have constipation not diarrhea, bloating and distension about 6-8" greater than normal, low iron, low WBC, nausea, low left side pain, gas, etc.  I cannot get into a gastroenterologist for several weeks, but I am worried and obsessing about the bloat-I look very pregnant!  I also suffer from sacroiiliac pain, low back pain, and pain in the joints of my hands and feet.  Any help or suggestions will be greatly appreciated!