After reading through your experiences @electracat, I see a lot of similarities to my issues. I had about 5 ft. of my terminal ileum removed almost 5 years ago due to a cecal volvulous, and now am considered to have short bowel syndrome. Once my small intestines adapted to less length and surface area (which they do...amazing), my issues with constipation that I had prior to the volvulous returned. I HAVE had the motility studies done (Sitz markers, gastric emptying, colonoscopy, various defecation studies) . While I also have a tortuous colon, it seems that 2 other factors are contributing to my bowel issues. One is pelvic floor dysfunction. My muscles down there contract instead of relax when it's time for a BM. I have been through pelvic floor PT twice, and the best tool I have right now is a pelvic wand. I cannot live without it! Second, I have borderline rapid gastric emptying, which is probably why I, like you, see a lot of undigested food particles in my stool, sometimes as aoon as 2 hours after a meal. I hope this is helpful as I didn't see anyone else mention these two topics.