He won't talk to me about it.

thats scary not knowing whats going on with him!
As for why he may not talk to you anymore, getting an ostomy is a scary thing to a person and its hard to come to grips with at first. And he may feel like you will not want to be his friend or date him now that he has this bag. Which obviously you don't care, but its hard for someone to believe that sometimes. and some people see having a bag as something that they cant deal with. you said he shut down towards you after a death in the family and that shows that when he has something happen in his life like that he woudl rather deal with it alone. Which some people are just like that, thats not something you should take personally.
Anyway, i woudl think that most likely he is just so upset about having the bag himself and finds it hard to believe, regardless of what you say, that you really dont care about it.

What I discovered after having had rectal cancer (see my bio) and 2 surgeries 10 years ago and joining several medical forums, is that for each patient (and caregiver/friend/family), they have their own individual response to this surgery. Some handle it easily, have very few problems, will talk about it to anyone who will listen, and then others clam up and won't discuss it. At all. In time perhaps your friend will come around and seek you out. I would leave the door open for that possibility. You can't force him to speak up about his situation. He has to be ready to talk about it.

Your topic reminds of the day I had what I called a mini-breakdown. Post resection, temp ostomy stage. I absolutely could not stop crying. I cried all day long! For all sorts of reasons, having had cancer, having a temporary colostomy, being in so much pain, the fact that I was still on ice chips, I couldn't see my daughters (3rd and 6th graders then) but my husband had been visiting (bless his heart), my dad who had passed away 11 years prior, I wanted him to just hold my hand.

Then my ET nurse walked in to check on me. My phone rang. 5 friends I had known since high school wanted to have "lunch" with me. They wanted to come sit and visit with me. I said - but I am not eating yet! They didn't mind. My nurse looked at me, at that phone and said, hang up. I quickly got off the phone. She asked me a series of questions - do you want to answer your phone? No. Done, she had the wringer turned off (I could call out and I promptly cancelled that lunch nice gesture, they did mean well). She asked if I wanted visitors - NO! She posted a do not disturb sign.

Then she sat on my bed and held my hand. Allowing me to cry. I cried all the more when she did this!

She then explained to me that women have an outlet for all this grief and emotions. We cry. We rant. We rant, rave, shake our fist at the world. In other words, we let it out.

She said men have a much harder time adjusting to ostomies. They internalize all of their emotions and try to cover up any concerns they have. If they have trouble, they don't tell nurses about it. They fake it.

This is when I looked down at my stoma and thought - okay, I have changed a lot of messy diapers in my day (baby-sitting too, with cloth diapers, you rinsed in a toilet!), handled extremely heavy periods too, I can handle an ostomy.

I could have handled it for life, truth be known.

But I had mine reversed.

Your friend might be having a very easy time with all of this. And if so, more power to him. Horray! But if not, he is probably uncomfortable talking about it. Give him time and space.

Sometimes just holding someone else's hand and let them do all the talking, is what works. Silence. And good listening skills.

God Bless My former Ostomy Nurse! What a sweetheart she was.......one of a kind.

I wish you well. Please don't drop this friend. He may need you down the road.