According to NIH:
It is believed that due to the continually unsatisfactory success rate of corrective surgery, indications for surgical treatment of parastomal hernia are limited mainly to cases with severe symptoms and complications, occurring in roughly 30% of all hernia patients. In this context, the main indications and contraindications for surgery are as follows.
Absolute indications:
– incarceration,
– strangulation,
– obstruction,
– parastomal fistula,
– perforation,
– somal ischaemia.
Relative indications:
– history of incarceration,
– recurrent temporary symptoms of obstruction,
– difficulty in maintaining the collection device,
– inability to visually control and treat the stoma,
– problems with irrigation,
– hernia-related pain,
– erosion of the surrounding skin,
– inability to accept the stoma aesthetically,
– narrow hernia gate resulting in difficulty in its reduction,
– other concomitant complications with indication for intervention, e.g. stenosis or prolapsed.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5890847/