I have IBS and pain in lower left on and off

I been having pain just a little left below my belly button. Some days no pain at all. The pain can be very strong and keep me up all night even after taking two 650 mg of Tylenol. All blood work normal. CT scan Sever chronic Diverticulosis and I was told I have IBS. They gave me Dicyclomine 20 mg, Canasa suppositories and Miralax . I been taking Metamucel once daily and have had regular bowel movements. Why am I having this terrible pain on and off. Why give me Canasa, I read its for colitis.....

Post Edited (Empirestate) : 8/18/2017 3:51:28 PM (GMT-6)

I feel like I have to push every time I sit on the toilet. I called the nurse and she said I do not have Colitis and that the Canasa is use for other thing. I went to my regular Doctor who told me to stop taking the Dicyclomine 20mg. He put me on Anti depression medication Escitalopram 10 mg that I have been doing for a week now and I still do the Metamucil and miralax. I am still having my ups and downs with the pain. Doctor told me it would take about a month. Thank you for reponding