Hernia repair frequently employs surgical mesh. However, potential complications exist, including mesh migration into adjacent organs, leading to serious outcomes such as enteric fistulas. We report an unprecedented case of composite mesh leading to gastric penetration and subsequent gastrocutaneous fistula formation, identified during endoscopic investigation as a foreign body. A 70-year-old man who underwent right hemicolectomy and incisional hernia repair using composite mesh presented in with symptoms of intestinal obstruction and a small bowel content leak. Following these complications, a small bowel resection was performed, and an ileostomy was created. During an endoscopic investigation, the composite mesh used in the hernia repair during the ileostomy creation was found as a foreign body penetrating the gastric antral area, causing a gastrocutaneous fistula. An exploratory laparotomy was successfully carried out. This case highlights the need to consider mesh-related complications and advocates for research into prevention and management of such adverse outcomes.