Hi, welcome to Healingwell :) I was on and off Rowasa for many years. And I didn't actually build up a tolerance but rather an intolerance. I can no longer do mesalamines because it increase my D severely and it also gives me severe abdominal pain with a flu like feeling. Before the bad intolerance issue, Rowasa or Canasa would just increase my D. So yes, some people can begin to have an intolerance to this med. As for the generic and brand name; I found that the generic made me worse then the brand. So you can try switching to the brand name if you think this is the problem.
Moderator for Allergies/Asthma and Co-moderator for UC
~Left sided Uc-'92-Colazal(9 daily),6mp(50-100mgs),Prilosec,Biotin,Forvia,Pro-Bio**Unable to tolerate Asacol, Rowasa or Canasa**~Year-round allergies-Singulair, Allegra~Secondary Reynauds Syndrome-'04-Norvasc~Spinal Stenosis(?)~Sacroiliitis-epidural injections~bulging and herniated discs C5/C6 & C6/C7~2nd epidural injection 8/14, Neurontin and Skelaxin
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