My name is Marsha, and I've had my ileostomy for 50+ years, since I was 15. I'm 68 now. I had ulcerative colitis, and so my whole colon ( large intestine) was diseased, and had to be removed. I had no choice in the matter. But the doctors didn't want to removed the rectum, in case "some day" technology would advance and I could have a reversal. I was 19, and I told them to "take it out"! I would never opt for a reversal, and the chance of more disease.
Obviously, if you have an ileostomy now, but you can have it changed to a colostomy, then you have an intact colon. Personally, there are pros and cons, for each......if one has a choice. But going through a major surgery, and adjust to the new situation is something only you can decide.
As you must know from experience, an ileostomy flows continually.....not really possible to regulate, and generally speaking the output is somewhat liquid to loose, given that fluid hasn't been absorbed by an active colon.
With a colostomy, the opening ( stoma) is made somewhere in the colon......so the output varies as to how much of a colon you have. If you have the full colon, waste is going to be firmer, and will push out "whenever", unless you irrigate . That involves a daily procedure of putting water into your bowels, via a tube into your stoma, ( like an old fashioned enema), The waste will soften, and loosen, and then flow out ( into a long pouch/ sleeve) which you attach much the same way as you do an ileostomy flange. The upside for some is choosing the time they want to "evacuate". ( I think the procedure takes about an hour). Some do it in the morning, others in the evening...whatever works for you. If you don't irrigate, than the consistancy will be firm, and you'd need to wear a pouch as you do now.
I hope that answers the questions you may have. I'm use to what I have, and wouldn't want to change, but if I'd had a colostomy, that's what I would have adjusted to. Best of luck with your decisions...