• rectum
  • The disease is classified by the extent of involvement, depending on how far the disease extends: Distal colitis, potentially treatable with enemas:Proctitis: Involvement limited to the rectum. (wikipedia.org)
  • often
  • Ulcerative colitis most often begins gradually and can become worse over time. (nih.gov)
  • ASCAs and perinuclear antineutrophil cytoplasmic antibodies (pANCAs) are the two most useful and often discriminating biomarkers for colitis. (wikipedia.org)