Does Taking Zofran Cause Constipation?

No bowel movement x 4 days despite Kristalose, Amitiza (24 mg, bid), Mag Citrate. Have been prescribed Zofran for nausea associated with the constipation, but have read that zofran can cause constipation... I called my gastro, but they weren't helpful. I have had 9 EGD's and colonoscopies for IBS, was found to have "very sharp turns" in my upper colon. I can actually feel the stool... but am bleeding due to the straining. (not blood IN the stool, occult stool test ruled that out)... can zofran cause constipation?? I've had an impaction before, and i know what it feels like. I think I'm headed in that direction!!