"Tell me you've had worse", says the OP. OK then! I've used a new account for this, because this is so bad that namechanging alone wasn't going to cut it.
Mine happened today, and I'm still mortified right now.
While on the walk home from this morning's school run, I had the most awful urge to go to the toilet out of nowhere with absolutely no chance of making it home in time. Thankfully I was just around the corner from my GP's surgery so I made a (very) quick detour and asked the receptionist if they had a loo I could use. This would have been a fairly straightforward endeavour, had she actually heard me when I tried to ask discreetly for the toilet, but she didn't, so I had to repeat myself, loud enough for people in the waiting room to hear. When she finally figured out what I wanted, she replied that the toilet was really only for patient use, so I had to explain to her that I was a patient, just one without an appointment right now, but I was having an emergency and could she please just show/tell me where the toilet was. At this point she took pity on me and pointed behind me towards the lav, which turned out to be immediately off the waiting room opposite the reception desk - clearly not ideal in terms of privacy but I dived in anyway because I was literally on the point of crapping myself by then. It was so urgent I honestly thought I'd be in and out like lightning and nobody would be any the wiser that I wasn't just having a wee, but no such luck - I've never had the runs like it, and was stuck in the toilet for a good 20 minutes and it was not pretty, and not quiet, no doubt to the delight of the 10 or so people sitting in the waiting room who could probably hear the whole thing.
As if doing the walk of shame past everyone in the waiting room having been (audibly) in the loo having the runs for 20+ minutes wasn't embarrassing enough, I didn't even make it to the front door of the building before another stomach cramp hit me and I needed to go again really urgently. So I immediately had to turn around and do another walk of shame back to the toilet and go in again, in front of the same 10 people who'd seen me come out not ten seconds before, where I spent what felt like another eternity welded to this bog that afforded absolutely no privacy whatsoever from all the people on the other side of the thin wall.
To top it off nicely, after I'd been on the toilet for about half an hour - for the second time - someone, I presume one of the receptionists, knocked on the door and said "Excuse me, you've been in there for a really long time, are you OK?" I tried just ignoring her, but she kept bloody knocking, and in the end all I could think of to say to get rid of her was "I'm really sorry... I've got the runs... I'll be out as soon as I can but it might be a while..." So the whole waiting room now knew I had the runs, as if the half an hour on the bog for the second time in rapid succession wasn't enough to clue them in in the first place.
When I finally made it off the toilet, everyone looked at me funny when I came out, and I'm not surprised because that second visit was at least 45 minutes long, probably even a bit longer if I'm honest :(
TL;DR - this morning, I was on the toilet for well over an hour, in two shifts, having the very urgent, extremely lengthy and fairly noisy runs, in front of a GP's waiting room full of people who heard the whole thing, and one of the receptionists noticed how long I'd been in there and knocked on the door half an hour into my second trip :(
Please someone tell me they've had a more mortifying morning than I did today. I'm going to have to move house so I can change surgeries, aren't I?