These intestines were a completely unique item and there is only one way to acquire them within the game.
Following the game's main storyline, the player would end up in an area known as the 'Trash Warrens'. At this point the player could fight through the various enemies in the warrens and eventually make his way to the underground city where the intestines can be acquired (it should be noted that The Nameless One technically already had the intestines; "acquiring them" merely amounts to them being placed in your inventory) or the player can simply allow himself to be killed in combat, which, in following with the game's lore, will simply result in him waking up somewhere else; in this case, within the morgue of the underground city.
Upon waking, The Nameless One finds himself upon a stone table with a blind old woman named "Marta" near him, who is described by in-game text to be busy popping the teeth out of the mouths of the dead. After a brief introductory sequence, the player may choose to engage Marta in dialogue, and, through several dialogue choices, may ask her to search several different areas of his body for items. If the player chooses to let Marta search his abdomen, the player will have The Nameless One's intestines added to his inventory, along with a ring that Marta located inside of his intestines.
Dying is unnecessary. You can have the same conversation, with the same results, merely by speaking with her.
The intestines should be kept, as they come into play when the Nameless One recruits Ignus into his party.