I remember coming home from dinner with my family when I was little. I'm not sure of the exact year, but I remember I had played in one of those pits full of balls that kids can jump in. I went to the bathroom, dumped a load, and flushed. Later my mom and I were brushing our teeth in the bathroom when she said, "Gee, it stinks in here. You need to flush after you poop." I insisted that I had flushed, and proceeded to lift the lid of the toilet to show her.
There, in the bottom of the bowl, lay the turd I had passed earlier.
I was dumbstruck and terrorized. At that moment, something in my mind clicked, and I knew I could never poop in that toilet again. I ran from the room and hid as my dad placidly plunged the toilet.
Fortunately there was another bathroom in my house, and I used that for several years before the turds I made began to get bigger and more likely to get stuck in the toilet (I was growing, too). I was afraid of toilets to the extent that I had nightmares about them overflowing, so using a plunger was out of the question. My only solution was to completely stop crapping in the home toilets.
I went at school, at my friends' houses (until my best friend's mom commented on the fact that I had clogged up their toilet), and restaurants. It became a standing joke in my family that I had to go to the bathroom after eating a restaurant meal (I told you it was like an eating disorder, right?). During the summer I made trips to the public library several times a week. Even when I got older and could deal with malfunctioning toilets to a small degree (like fiddling with the float to make it stop running), I was terrified of clogging up someone's toilet and having them notice.
It was a vicious cycle. I wanted to poop but had to wait until the right opportunity. As a result, my turds were huge and therefore would have clogged up my home toilets. See my logic?
At times I went for a week without going just because I had no opportunity. When my mom took me around on her errands I was in constant discomfort -- all I ever wanted was to sit down. I once went for a hike with my Girl Scout troop and sat down every few hundred feet or so. When we got back to the cabin, I ran for the bathroom. I remember being in middle school, lying awake one night, knowing that I really needed to poop, afraid that I would be too constipated the next morning. Once, when we were picking up my grandma at the airport, I ran into the airport bathroom, took the quickest shit of my career, and then dashed out to the car again before my mom had to circle around. I once pooped in the backyard, and once in my bedroom -- I carried the turd to the kitchen trash with my bare hands.
I was a freshman in high school when I got really constipated. I had been constipated before, so I don't know what was different this time. I finally told my mom that the problems I had had pooping as a little kid had never gone away. She gave me a bunch of tea and prunes. She said that the next morning I would get up and poop in the home toilet, and that she didn't care at all if I clogged it up.
I got up and pooped. It was a difficult crap because I was somewhat constipated, but it did the trick. Since then, I have used the home toilets, and have even learned to use a plunger. Still, for a few years after I learned how to poop at home, I was a little skittish around toilets.
At this point, though, my phobia has finally left me. I still don't have the most regular bowel patterns, but I never go as long between dumps as I did when I was in grade school. I am a devoted squat-shitter because it gives me more power and keeps me from getting hemorrhoids. And I try to keep my bowels healthy to make up for the abuse I gave them when I was younger.