What Causes Abdominal Cramping And Constipation With History Of Chronic Diarrhea?

Spent 7 days in hospital for cronic diarrea 9yrs ago. Have been on Asacol 800 mg (1 tablet) per day for last several yrs. Job changed insurance. Did not cover Asacol so was perscribed balsalazide 750mg (1 tab/daily) last 2 weeks. Slight cramping, some constipation & bowl movements maybe every 2 days. Is this due to changing meds?