The Danish study is prospective in nature, which distinguishes it from most other studies on the health effects of cell phone use, which were case-control studies and enrolled subjects diagnosed with brain tumors and a comparisongroup of subjects who were free of brain tumors in order to compare reported cell phone usage in the two groups.
One examined 29 patients with Crohn's disease and found that after six months, 21 were considered remitted. (There wasn't a controlgroup for comparison.) The other was study of 54 patients with ulcerative colitis.