Odd Posture to Poop

Q: I have a 9-year-old gelding who holds his body in a strange position while defecating. He curves his head to the left, then brings the left hind leg forward while passing feces. His whole body is in a curve to the left … There was a period of about a year where he colicked frequently, about every two to three weeks. Usually it was relieved with walking and Banamine. I did have a vet do a rectal exam to check for anatomical issues, but nothing was found. Despite using psyllium for four to five days per month, he was still colicking, so we ruled out sand colic … but the question is whether the strange body posturing is related to having had colic often (this was about two to three years ago) … Any ideas why?