I Have Non Surgical Related Dumping Syndrome And Suffer From

I have non surgical related dumping syndrome and suffer from severe constipation. I am on a 2500 cc fluid restriction. ! take 4 pericolace every night. I have gone 4 - 5 days between BM's despite taking 60cc milk of meg and 4 Dulcolax. Any suggestions on diet or anything else? I do take many medications for mental illness, diuretics for PH.