If you believe the fish is having trouble passing it's food, start feeding a little Spirulina. It's high nutrient and a good source of fiber. You can also gradually increase your water changes to half the tank's volume every week. I would recommend using water that's a bit warmer. This will increase the fish's metabolism a little. You can raise the setting on the heater a little. The combination of warmer water and little fiber, should help.
"Fear not, my young apprentice. Just change the tank water."