Srimad Bhagavatam Canto 04, Chapter 25, Text 53

SB 4.25.53

nirrtir nama pascad dvas
 taya yati purañjanah
vaisasam nama visayam
 lubdhakena samanvitah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Another gate on the western side was known as Nirrti. Purañjana used to go through this gate to the place known as Vaisasa, accompanied by his friend Lubdhaka.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
This is a reference to the rectum. The rectum is supposed to be situated on the western side of the eyes, nose and ears. This gate is especially meant for death. When an ordinary living entity abandons his present body, he passes through the rectum. It is therefore painful. When one is called by nature to evacuate, one also experiences pain. The friend of the living entity who accompanies him through this gate is named Lubdhaka, which means “greed.” Due to our greed, we eat unnecessarily, and such gluttony causes pain at the time of evacuation. The conclusion is that the living entity feels well if he evacuates properly. This gate is known as Nirrti, or the painful gate.
Srimad Bhagavatam Canto 04, Chapter 25, Text 52
Srimad Bhagavatam Canto 04, Chapter 25, Text 54