My mom (86) was taken to the hospital and has a major bowel blockage. How do we deal with outsiders telling us what we should have done?

My stepmother had the perfect answer when an acquaintance asked why my dad was being cared for by hospice. She said "i can't imagine why you think that is any of your concern". In her sweet Australian accent, it shut people down in their tracks.

For starters it is too late, but the way to avoid this all is to stop giving these folks all the medical information you are giving them. Because now you will get all the "My aunt IRMA was NINETY NINE years old and SHE did just fine with surgery" and so on.
So just say in future "I am sorry. Medical information is private and I am not comfortable discussing Mom's diagnosis, prognosis and choices with you. Please refrain from discussed medical problems with her. She is on hospice and she is actively dying. Please honor her wishes for peace so that I can allow you still to enjoy happy visits and memories with her her".
The end. Full stop. This is not their business, but people are busy-bodies, and that has been true forever.
I am so sorry for this loss. I am so thankful you are honoring your Mom's wishes and that you are at peace and she is being kept comfortable.

I don’t think they deserve any answer. A quiet stare and walk away should be enough.

I work in an office with a number of passive aggressive people that can't or won't mind their business. In a meeting one time I let the group know that I had a standard physical scheduled and it could take some time because I was due for some routine tests, EKG, etc. and that I would be in ASAP afterward. One of my coworkers wrote in her "daily work chart" ______'s Physical. As we return to working together this behavior has been frowned upon because we have all have to stop this toxic behavior. My supervisor gave me the best advice....... I will share. Look at them, give them a week stupid smile and say in your best slightly irritated voice "What an odd thing for you to ask, say, do, etc" and if they press the matter just stop talking and wait for them to walk off.

Sometimes the best answer is NO answer. Just silence. OR if you feel you need to explain, you can say "Why in the world would you ask such a personal question?"

That will shut up the most aggressive soul--but I have only used it once or twice.

Her body, her life, her choice. You made the right decision by supporting her. The rest is just noise.

I can think of a variety of colourful phrases to tell them, but would probably get banned from the forum for posting them.

Good for you for carrying out her wishes.

Tell them, "Mom is in her right mind so the decision is hers. We will abide with her wishes."

Another comeback could be, “I didn’t ask for your opinion.”

You answered your own question with a great reply....

 "She made the right decision for her. She was at peace."
"My dad & sister both died of cancer in their 50’s mom is content about reuniting with them & the rest of her family."