Stage 4 rectocolon cancer

[Maie4842]

Son diagnosed 12/2018 with colorectal cancer. Tumor removed 9/2019 post chemo and radiation. Reconnect 11/2019 and two days later rushed to ICU and surgery for complete lg colon removal due to CDIFF  as total toxicity through out body. Onintubated and in ICU for one week. Family notified he may not survive, but he did. In 1/2020 complained of discomfort when sitting. Dr said residual pain.  COVID prevented him from getting treatment until 1/2021 at which time told stage 4 with mestastisis to lung, groin and site of original tumor. Although in pain was told no major surgery could be done to his history of CDIFF but due to lg fistula at stoma site they could take care of that. Is it safe to have fistula repaired ?  He has a huge hernia from the emergency surgery as they couldn't reconnect the abdominal muscles and they won't do that either. He is again on chemo and no prognosis has been given. Also any ideas for rectal pain other than norco. Anything natural. He hates copy feeling from pain meds.
Thank you MR