May Be Caused by

 Common

Ascaris

Breast cancer metastasis

Brunner gland hyperplasia

Food particles

Foreign bodies

Kaposi sarcoma

Meconium ileus

Metastatic lung cancer

Metastatic melanoma

Metastatic ovarian cancer

Nodular lymphoid hyperplasia

Pill ingestion

Polyposis syndrome

Seeds

Tapeworm

 Uncommon

Amyloidosis

Behçet disease

Blood clot

Carcinoid

Crohn disease

Enterolith

Gallstones

Gastrointestinal stromal tumor

Hemangioma

Hyperplastic Peyer patches in ileum

Leiomyoma

Lipoma

Mastocytosis

Neurofibroma

Varices