Postoperative gastrointestinal dysfunction and gastrointestinal tumors: A review and a point of view

Table 1 Prospective studies on the patient-related non-modifiable factors

Ref.	Comments
Wang et al[7]	Age as one of seven independent risk factors
Yoshiyama et al[42]	Age ≥ 75 years was an independent predictor of postoperative swallowing dysfunction, with an odds ratio of 2.56
Ji et al[43]	Surgery and anesthesia can induce cognitive impairment potentially linked to abnormal complement signaling and synaptic disruption
Xie et al[36]	The technical difficulty of the operation is a key risk factor for postoperative ileus. Patients with advanced cancer frequently present with preoperative comorbidity, indicating that their baseline GI function is already impaired prior to surgery
Lang et al[44]	Estrogens may offer protective effects on the GI tract

GI: Gastrointestinal.