TABLE 3.

Gastrointestinal causes of iron deficiency and iron deficiency anemia.

Factors associated with gastrointestinal bleeding (macro or microscopic): • Gastroduodenal peptic ulcer/Heliobacter pylori infection • Hemorrhage due to esophagogastric varices • Portal hypertension gastropathy • Gastric antral vascular ectasia • Angiodysplasia • Inflammatory bowel disease • Use of acetylsalicylic acid or other non-steroidal anti-inflammatory drugs • Gastrointestinal malignancies • Diverticular bleeding • Hemorrhoid bleeding • Postoperative bleeding • Large hiatus hernias (Cameron lesions) • Parasitic infections

Factors associated with impaired absorption due to limited availability of or damage to enterocytes: • Low-iron diets • Chronic autoimmune atrophic gastritis • Celiac disease/non-celiac gluten sensitivity • Inflammatory bowel disease • Intestinal lymphoma • Bariatric surgery/gastric bypass surgery • Short bowel syndrome • Gastrectomy or gastrojejunostomy • Bacterial overgrowth