After adequate counseling with life-style changes (mainly consumption of more than 90 g/day of high biological value protein), supplementation with pancreatic enzymes, and management of contributing medical conditions (such as gastroenteritis, lactose intolerance, intestinal bacterial overgrowth syndrome, celiac sprue, and inflammatory bowel disease), recurrent or severe PCM is frequently caused by excessive malabsorption. When mild or moderate protein malnutrition is instated, two to three weeks of parenteral nutrition are generally required to revert it. In contrast, severe PCM refers to the need for prolonged total parenteral nutrition "TPN", recurrent need for TPN, or malnutrition recalcitrant to TPN. Eventually, revisional surgery is required. The recurrent or severe form of PM is rarely secondary to excessive persistence of the food limitation mechanism with or without poor protein intake, requiring restitution of the intestinal continuity or complete reconstruction of the gastrointestinal tract (partial vs. full restoration). The partial restoration of the gastrointestinal tract allows normal protein-energy absorption, still partially preserving the specific effects of BPD on glucose and cholesterol metabolism.