since my mid 20 s i have had a tendency to be constipated and about 13 yrs ago i was diagnosed with ibs . i am 42 yrs old now and and have always been able to control it with diet. about 2 or 3 months ago i could no longer control it. no amount of fiber or water consumption helped. i ended up at a carenow clinic and was given a bunch of laxatives. i was able to go as long as my stool was liquified. i followed up with my regular doc and she prescribed amitiza . it helped somewhat for a short amount of time. although i never felt like i had real relief.i go 5 or 6 days at a time unable to go. she gave a me a sample of linzess which just gave me diarrhea . she sent me to a specialist and i have a colonoscopy scheduleded for tuesday. when i went on monday i was told to use miralax and a probiotic daily as it might help. i have not had a bowel movement since last sunday. i guess my question is what could be going on? i am on a strict diet which mainly consists of vegetables and fruits. i drink close to a 100 oz of water a day. im taking miralax and a probiotic. why would i not be able to go to the bathroom?