Inoperable rectal tumour / bypass operation

Does anyone have any experience of having a bypass operation to try and ease symptoms of an inoperable tumour? 

Some background, my mum (aged 77 now) was diagnosed with Stage 4 rectal cancer in Oct 2022, with spread to her liver.  She underwent radiotherapy followed by 3 months chemo which she tolorated brilliantly.  She then had a liver resection which again went well and prepared to have her bowel resection last August.  Unfortunately, when they went to operate they said the tumour had fixed to her pelvic bone and was now inoperable:-(  they rescanned and discovered further spread again to the liver and lungs.  She went straight back onto chemo for 6 months which she again coped well with until the very last cycle when she seemed to just fall apart, sudden hair loss, weight loss and dramatic drop in appetite and energy..she really struggled.  We were told after her last scan that things were 'stable' and so she is now on a 3 month break from treatment.  But she is really struggling with the worsening side effects of still having the rectal tumor, awful bowel issues, having to take constant codine for the discomfort and trying to get the balance between constipation and diarrhoea. She also has bleeding on and off which they said was to be expected.  We have an appointment in 2 weeks to discuss possible bypass surgery to divert to a stoma, but a consultant told us that she would still have the same discomfort and bleeding as the tumour is still there.. so just wanted to see if anyone had any experience of having a bypass and whether it has improved their quality of life?  I know it would still be a major operation, especially when she seems so much weaker now than before.

Just as an aside, I have asked to be referred for a second opinion on whether the tumour can be removed at all now that she is considered stable.  I feel we need to at least ask that question.

Thanks and sorry for the long post!