Suggest Remedy For Chronic Constipation Due To IBS While On Miralax

Hi, I have been having bowel issues for quite sometime. The last time I saw my doctor, he diagnosed me with IBS with constipation. He told me to take half cap full of Miralax daily, it was working. I have been taking it for about four months. Now, I have added colace to my bowel regimen, because I feel that when I have a bowel movement it is small and I don t fully go and I have been feeling bloated with some nausea. Do you suggest any tests that my doctor can do for the next step. I still feel constipated, please help! FYI, my mother had ulcerative colitis, started in her twenties. But, she passed away from a brain tumor.