I'm sure those of you who have suffered from this have heard of this but I'll post it just in case. I used to suffer from this a lot and it was miserable. My low point was one time before ds. I was working for a company and had an important meeting set up with a big client in Paris the next day. I was going with my boss but I was taking
the bulk of the meeting.
I left the office the evening before and that night I started getting cystitis symptoms. It was excruciating by the morning (I was up all night with it) and I was forced to get a train to Waterloo from my house to meet my boss at the Eurostar terminal. I had some really important papers for the meeting and I was supposed to be doing a presentation too. I had to hand over the work to my boss and tell him I jusrt couldn't go. It was incredibly embarassing and by the time I go home I was sobbing with pain and had to wait hours for a GP appointment to boot.
Around that time I read a self-help book about it as I was getting desperate for help as I seemed to keep getting infections.
It offered the following advice about washing and hygiene following sex which I have taken ever since and haven't had a bout since then.
Washing
Was after EVERY bowel movement. Also the way to was is to use some soapy water actually on your bottom and then to pour warm water from a cup from the front to the back as you sit on the loo. Do this a couple of times to rinse.
I keep a cup in the bathroom specifically for this. Also do this in the morniing and before bedtime.
After sex
Always get up to pee afterwards (and I mean always). Then also do the washing technique above.
This all helps to ensure you reduce the chances of getting any bacteria in your urethra.
Also if ever get any vague symptoms. I can usually tell by the vague desire to keep weeing after after going to the loo or by that pressing sensation you sometimes get. Then I start to drink water like there is no tomorrow (1 large glass every half an hour for at least 3-4 hours). I have even stayed up during the night to do this if I had even an inkling that I might be getting a bout Also I take the stuff from the chemist. This works IF you catch it early enough.
However the single thing that helped most was the washing technique described and the weeing after sex.