OK, people, put your thinking caps on about my sick horse?

I would get rid of the alfalfa cubes. Feed some good quality hay and if you want increase his fiber intake, feed him sugar beet pulp soaked in water. Horses that have colic, especially senior horses are more prone to repeat. He could have mild colic now. You should call your vet. Eliminate grain and and other feed from his diet. Good hay and available water is best.