I am afraid you probably have a fistula in-ano again. This may be because the previous one has reformed or a new gland in the anus has got infected. Recurrence occurs in about 10% of cases after operation and is usually due to the walls of the excised fistula coming together and reforming the tunnel. It is sometimes, but very rarely, due to diseases like tuberculosis or Crohns. I would advise you to consult the surgeon who performed the original operation.