If you eat a small piece of your shirt, you will definitely have constipation when you go to the bathroom. The fiber in your shirt's textile is indigestible and it would disturb your digestive system once you swallow it.
choking is possible i would not recommend doing this and it might even screw up your intestine system. Constipation will definately occur. But hey if you like pain and/or spending multiple hours on the toilet go ahead