“…The gas is thought to come from the intraluminal gastrointestinal system, bacterial production, or a pulmonary source [ 3 ]. Besides chemotherapy, PI is associated with various medical conditions, such as collagen-vascular diseases, lupus enteritis, infectious colitis, asthma, acquired immune deficiency syndrome, cystic fibrosis, hematopoietic stem cell transplantation, trauma, and steroid therapy [ 2 – 4 ]. Compared with cytotoxic agents, PI due to molecular-targeted agents is even rarer [ 1 , 5 – 12 ], and only several cases have been reported in association with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) [ 1 , 13 – 17 ].…”