I will try to be brief as possible. Hope this helps.
I was having problems with painful fissures for approximately three years with trips to the doctor with both my general practitioner and surgeons. The fissures would generally last for 1-1/2 months and then go away for several months or a year, and then ultimately always come back. The pain was mind-bending. Then toward the end of the three years, my GP told me "the colo-rectal surgeon made a note that you have a tight rectum, but I don't recommend surgery because then you will have a loose rectum, and with it comes a whole other subset of problems."
That set about a change in my thinking. I had to do something, though, because the spasms and pain were unbearable. There is a journal study that is readily searchable on the internet that concludes that manual dilation is 80% effective when using a finger, and 60% effective when using a dilator (butt plug). So I figured this was worth a try.
For 10 months I used butt plugs starting small at under an inch and going up to 1.33 inch diameter. I had no desire or need to go larger than that. The spasms stopped pretty soon after I started using the smaller plugs. There would be blood and new fissures on probably 8 different occasions, resulting in heartache because I didn't know how far the new fissure had set me back and if I was back to square one or not. Turns out in all cases, I wasn't back to square one, but the fissures healed much sooner and with fewer spasms at first, and then no spasms after a few months. The last 3 or 4 times there was blood due to a new fissure, it basically felt like a sunburn on the bumhole that seriously lasted only one day!
My anal region feels much stronger and now I am confident that manual dilation has worked. There has been no blood when using plugs for the last several months now. However, I think I could have avoided breaking open new fissures if I used a finger for the first several months before moving on to the plugs. I went with plugs right away because I found that they are slightly easier than reaching all the way down with a finger. I haven't told the wife yet because I don't know what she would say...I guess now that I know it works, I should tell her too!