Gut Oxygen Therapy for Ischemic-Hypoxic Bowel Disease

Inclusion Criteria: * Definite diagnosis of chronic heart failure or obstructive sleep apnea (OSA) with chronic hypoxia; * Comorbid intestinal dysmotility (abdominal distension, constipation, diarrhea, or abdominal pain); * Disease duration ≥1 month with poor response to conventional treatment; * Tolerability of transendoscopic enteral tubing (TET) with successful placement of the tube at the ileocecal junction; * Age 18-80 years; * Able to cooperate with bed rest therapy and provide written informed consent. Exclusion Criteria: * Oxygenation index \>400 without supplemental oxygen and/or resting oxygen saturation ≥96%; * Primary organic gastrointestinal diseases, intestinal obstruction, inflammatory bowel disease, or severe hepatic/renal failure; * Hemodynamically unstable, unable to tolerate sequential intervention (time-sequenced intervention); * Presence of cough or spinal disorders that prevent maintaining a resting state during bed rest; * Failure of arterial catheterization or endoscopic tube placement; * Mental or cognitive impairment that precludes cooperation with assessments.