What is the main conflict in A Confederacy of Dunces by John Kennedy Toole?

Ignatius J. Reilly dresses eccentrically, holds a master's degree, has no job, is 30 years old, and lives with his widowed mother, Irene, in a dark, old house in New Orleans. He has left town only once in his life to apply for a teaching position in Baton Rouge, and that trip has become the defining event of his life, traumatizing him against travel and work. Ignatius is overweight, overeducated, and overindulged by his mother Irene. He watches television and movies and jots notes in notebooks, vaguely figuring someday to organize and publish them as a grand critique of the last four centuries of Western civilization, which he sees as steadily declining. He has rejected the Catholicism of his childhood, feeling himself superior to its lax, modern-day standards. Any amount of stress makes Ignatius' pyloric valve snap shut, causing him debilitating gas pains.