Treatment options for medication- and diet-resistant gastroparesis include drainage procedures such as pyloroplasty and gastric peroral endoscopic myotomy (G-POEM). While dumping syndrome (DS) and bile acid gastritis (BAG) have been documented as complications following pyloric drainage procedures, limited evidence exists concerning their incidence after pyloroplasty and G-POEM for refractory gastroparesis. We performed a systematic review of outcomes following pyloroplasty and G-POEM for refractory gastroparesis (PROSPERO: CRD42024559654). PubMed, Embase, Cochrane, and Web of Science databases were systematically searched for articles reporting rates of DS and BAG following pyloric drainage procedures. Assessed outcomes included rates of DS and BAG. Results were narratively synthesized and presented descriptively. Of the 2278 records reviewed, 10 studies were included. Six studies evaluated pyloroplasty, and four studies evaluated G-POEM. Nine studies reported incidence of DS, and two studies reported rates of BAG. The incidence of DS ranged from 0% to 23.1%, with a median incidence of 3.23% and an interquartile range of 6.95% among nine studies. The incidence of BAG ranged from 0% to 15.4% in two studies. The studies displayed high heterogeneity in study design, patient population, and co-interventions, precluding collective data analysis and limiting generalizability. All studies displayed a moderate to serious risk of bias. There exists a paucity of data regarding the incidence of DS and BAG following pyloroplasty and G-POEM for refractory gastroparesis. Despite the theoretical association of these complications with pylorus-modifying procedures, our findings suggest that they may be uncommon or underreported in the treatment of refractory gastroparesis. Improved reporting of these outcomes and robust prospective studies investigating the incidence of such complications are required.