Archaic or highly obscure term for the digestive organs, especially the stomach or intestines. Virtually never used in modern Japanese; the cross-reference to 糞袋 suggests a historical or dialectal synonym.
See also: 糞袋
In old documents, 糞腸 can refer to the stomach or intestines, but it is almost never used today.
Compound of 糞 (くそ, 'feces') and 腸 (わた, 'intestines'). The exact historical derivation is uncertain; it likely arose as a crude or colloquial term for the digestive tract.