The error was noticed when the operation theatre staff started counting their instruments after the 45-year-old woman's hysterectomy (removal of uterus) procedure and found a surgical clip missing.
The patient was admitted to the Nedumangad taluk hospital for hysterectomy procedure which was carried out on Thursday morning.
The technicians in the operation theatre sensed trouble when they noticed that a clip from the instruments tray was missing. They rushed the woman to the X-ray laboratory and found that the missing piece had remained within her stomach.
According to her relatives, they got restive and began to enquire when the woman was inexplicably kept inside the operation theatre for a long time even when the surgery had got over. The delay in wheeling her out worried them.
The woman was then taken to the Medical College Hospital in the state capital where the "foreign object" was removed from within her.
"The surgery went off well and the foreign object was removed and the patient is recovering," a statement from the hospital in Thiruvananthapuram said.
State Health Minister K.K. Shailaja said she has asked for a probe into the incident and has promised action.
