I think that a summary of Anand's work would have to focus on how Bakha's narration brings out both an understanding of his own characterization and a critique of the social condition of untouchability that was such a part of pre- Independence India.  Summarizing the book involves making mention of both critical points.  Bakha is presented as a narrator that is both seeking to understand his own condition in life and the social condition that enables untouchability to happen.  As this progresses, Bakha understands the Christian conception towards untouchability as well as the rise of the Ghandian call to end the condition in India.  Bakha's experiences help to illuminate both his own understanding and the construction of the world around him.  Essential points to bring out in a summary would reflect such insight, as well as the rejection that the nine year old experiences as a toilet cleaner.  As the principal character, Bakha becomes clear in his stance against untouchability, but also understands that the elimination of the condition that is so embedded in Indian society might only happen if individuals both rise up against it, but also if there is some assistance in its elimination from external forces.  In Bakha's case, technology, in the form of the automatic flush toilet, is where he might be able to see his own untouchable condition end.  It is in these points where the summary of Anand's work would have to focus.  The novel's summary rests in how Bakha is a vehicle to offer a social critique.  In summarizing the novel, the social condition has to occupy central importance, of which Bakha is a part.