Suggest Treatment For Constipation And Low Blood Count After Chemotherapy For Rectal Cancer

after going through chemo and radiation for anal rectal cancer they had to stop the treatment because its was making my blood counts dangerously low so i been having a lot of constipation and bowel movement problems and straining a lot to urinate what type of doctor should i seek for help? sorry i did not know their was a fee to get answer thanks anyway.