@literally45-- Yes, I have splenic flexure syndrome and I'm being treated with a high fiber diet and when necessary, a laxative.
My doctor is of the opinion that this syndrome tends to happen in people who don't eat enough fiber and get constipated often. Basically, when we're constipated, the stool has a hard time moving through the bowels. And since the splenic flexure is a hard curve, the stool causes pain and discomfort while passing through it.
I completely agree with him because ever since I have added more fiber to my diet and have regular bowel movements, the pain has reduced greatly. If I happen to eat bad for a day or two and get constipated, the pain comes back immediately.
So the key is eating healthy-- lots of vegetables, fruits and beans. Moderate activity daily like walking is also very helpful, so is drinking enough water! That's the cure to this syndrome.