The present disclosure relates to an (in situ gelling) enema containing Rifamycin SV and its use in the treatment of pouchitis, proctitis and/or distal ulcerative colitis (including proctosigmoiditis). More particularly, the present disclosure describes an in situ gelling retentive enema containing Rifamycin SV for treating, ameliorating, reducing the severity of or slowing the progression of pouchitis, proctitis and/or distal ulcerative colitis (including proctosigmoiditis).