effects of crohn's disease on chemo

My mother recently was diagnosed with Crohn's disease and soon after was diagnosed with lymphoma cancer.  She is currently recieving chemotherapy every three weeks.  right after her chemotherapy she experiences terrible constipation and has taken the medicine a gastroentologist has prescribed with no help.  three weeks ago she had to be hospitalized for two days the constipation was so bad.  The gastroentologist doesn't seem to take the crohns into consideration and possibility of blockage.  has anyone gone through anything like this? any recommendations for diet changes or what test to ask for?  any suggestions will be greaty appreciated, we are trying all we can to not have her have to be hospitalized again just for constipation.  She is in the Akron, Kent Ohio area so if you know of any specialist in that area that would be of any help, please let me know.