Fluoxetine

Advanced liver and gallbladder malignancies (including liver cancer, cholangiocarcinoma and gallbladder cancer) are a type of disease that is difficult to treat, and most patients have a short survival period. In recent years, immunotherapy (such as PD-1/PD-L1 inhibitors) has brought new hope to these patients, but still only a small number of patients can benefit. Research has found that approximately 40% of patients with liver and gallbladder tumors have symptoms of depression and anxiety, which not only affect their quality of life but may also reduce the therapeutic effect by influencing immune function. Fluoxetine is a commonly used antidepressant. The latest research shows that in addition to improving mood, it may also enhance the anti-tumor effect of immunotherapy. This study aims to explore whether fluoxetine combined with immunotherapy can better control tumors than immunotherapy alone, prolong the survival period of patients, and at the same time improve the depressive and anxious symptoms and quality of life of patients.

The goal of this observational study is to identify the characteristics of brain functional connectivity in refractory constipation and fluoxetine-sensitive patients. The main questions it aims to answer are: * Investigating the alterations in brain functional connectivity in patients with refractory constipation and fluoxetine-sensitive patients * Assessing the predictive value of brain functional connectivity regarding the efficacy of fluoxetine and standard protocol treatments for constipation. Participants will receive: * Standard physiological and psychological assessments of constipation * BOLD-fMRI tests * Standard protocol and fluoxetine treatment If there is a comparison group: Researchers will compare: Refractory group/Fluoxetine sensitive group to see the specific brain alterations.