Old long haired cat with cleaning issues

I have an older long hair cat that recently started having painful issues with her anal glands not emptying. I was told by the vet to add probiotics to her wet food. She has had problems cleaning debris(pooh )from her bum and would rub herself on the carpet until she would be excoriate and would require vet visits and antibiotics, but Ive started clipping the hair and wash her bottom regularly to prevent that. I recently noticed her limping so took her to the vet, and her anal gland required the vet to empty and told me about the probiotics. I’ve been to the vet 2-3 times because of her having a raw sore bottom on the outside in past 7 years and wondering why I was never told before about probiotics until now, too. Is this going to be an ongoing treatment?