Suggest Remedy For Abnormal Bowel Movements

My bowel movements have changed since about the end of Aug. (I did have a colonoscopy in May and my BM s were normal) It started out with lots of painful gas pains, smaller and more frequent movements, not much at all came out just mostly gas and a few small pieces, then I began to feel pressure at night on my bladder and am up at least 3 times and then I feel pressure on my abdomen/bladder and need to take Tylenol which does relieve the pain. I took a laxative on Mon. which seemed to help, but one day later am back to the same problems.(sometimes my stool has form to it, but small pieces) Plan to see my colonoscopy dr. Tues. My question would be...should I see him or a gynecologist? What would my bowels change so drastically?