I am so sorry to hear about the pain which your dear daughter is undergoing. I really don't have any answer, but can only pray that the things get fine very soon. I feel the patients with fistulas should not take too spicy or sour food, as it causes the fistula to misbehave. One should not sit on a hard surface for too long, if it is ano-fistula.
Take Care and keep us posted.
45 years Male Attorney
Diagnosed UC October 1989
Had two stage J Pouch Surgery Nov 2005; Take Down March 2006
Complications after surgery - Incisional Hernia and Ano Fistulas
"There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle: Albert Einstein
"What you are aware of you are in control of; what you are not aware of is in control of you."