[Hamtastic]

It could have been some extra strength paper towel that took too long to digest for a large amount he ingested. Some come with additional ingredients to increase strength. Normally you'd want to give him plain toilet paper ripped up a bit or very simple paper towel (nothing like extra strength fancily quilted in my opinion). I'd just stick to plain toiled paper for nesting though, it's thin and easier to digest if some ingestion happens.