Hi Happy,
So sorry to read of your suffering. An AF is horrible to deal with and I can imagine especially when you're having to go to school and deal with the toilets there and keep it quiet from others around you......
The good news is although it can take a while, you will get through it and feel better and normal again in the end. This doesn't last forever.
The Recto is good stuff, so keep using as you've been advised and hopefully, it will see you through the worst.
In response to your queries:
Lactulose can have an effect on your stomach, so could be causing some of the symptoms you describe but I suspect that with your sudden change in diet too, your body is adjusting! If you suddenly start eating lots of bran that can cause issues and it's always advised to build up slowly to minimise stuff like this happening. It should pass after a week or so though when your body gets used to the changes.
The most important thing you need to do is drink water like you've never drunk it before ( about 3 litres a day) but you can also have fruit juices (pure and not from concentrate are better) and fruit smoothies too. This will flush everything out nicely - just imagine your body itself being a bit like a toilet and you need to flush it to clear out all the waste!!.......
Looking at your diet, I would definitely suggest a few changes you could make.....Try brown rice (and unfried) instead of white. This is far more friendly for your body to digest & then poop! If you can lay off red meats and steak for a while, this will help a lot too as red meat is really hard to digest and can take a few days to clear out properly - Chicken/ Fish/ Turkey are much better at this stage, but again better baked/ steamed than fried/ battered etc.
Just try to cut down a little too on lots of buttery things - if you can switch the butter for Olive Oil, that's a great move.
To keep you more regular, lots of fresh fruits (figs & prunes!)/ apple purees/ soft cooked veggies/ salad/ beans & water!!
Reduce things like bread (eat wholemeal but no more than a couple of slices a day) Swap all the white foods for brown ones - like pasta/ rice/ bread products.....Try to avoid deep fried foods/ fries/ pies/ pasties/ cakes/ biscuits/ burgers - Yes, all the stuff we all love!!.....but it does help.......If you drink alcohol, keep it minimal and drink lots of water at the same time because this will dehydrate you.
Also try to stick to eating regular meals at regular times because this will also help you to get into a routine too with your BMs.
I use Vaseline before a BM to help lubricate my bum so everything passes out more easily & I used to apply Coconut Oil after a BM, once I'd cleaned up because I found it really soothing - You could really use either though before a BM.
Magnesium also really helps me to keep my stools soft but of course, you need to make sure you're eating all the right foods in the first place to create good stools. I take a supplement every night and in the end, as I got better, stopped taking Lactulose and switched to Magnesium instead. You have to experiment a little to see what works best for you personally.
Try to relax about your next BM because worry makes things so much worse. Just remember for some people, one BM every couple of days is actually normal - for others it's maybe 3 times a day!! It really depends on the person and as long as what is coming out is soft & healthy, then that's the most important thing. If you start to do all the above, you WILL start to improve your BMs a lot.
Being at school, it might be a good idea to talk to a sympathetic teacher if you have one, about all your issues. This way, the school can help you out and make special allowances for you too - They will be more understanding if you need time off or need time alone because you are maybe struggling sometime?? The more people you can be open with, the easier sometimes it is to deal with it all, but obviously it's up to you to choose people you know you can trust in.
I always carried a small pack of wipes and a small tub of vaseline in my bag for work, so these will help you too if you need to go to the toilet at school. If you have a lot of pain, it's good to carry a small packet of pain killers too.....
During the time of the month! - Yes lots of us women here have been through that one too and the main thing is just to carry on as normal!....Just drink lots of fluids again and up your fruits too.....there's not too much more you can do other than make sure you are keeping your body hydrated properly.
I hope this helps you you more & I'm sure others will help you out with their own tips too. We all understand each other here, which is a great comfort!! - So if you're feeling alone with it all, just come back & chat anytime. I also felt like I used to drive everyone mad going on about my bum!!!!
Try not to get too down about it all because you will get better in the end. It's just not a nice thing to deal with in the meantime but we are all here for you. Take Care poppet x x

And probably the most important thing of all!.........
When you go to the loo, try not to push anything out yourself at all!!
This can take a little time to learn but straining is what seems the biggest cause of all for fissures and retearing them. Once you start to eat better, your stools will be able to fall out all by themselves quite naturally and if you start doing this for life, your bum will be much happier :)