Iron is actively absorbed in
Active absorption of iron occurs in duodenum & proximal jejunum. In stomach absorption of alcohol (20%) & drugs like aspirin takes place. In large intestine, absorption of acids and bases, water, remainder of sodium (Na) and potassium (K) i.e. remaining because not already absorbed in the small intestine takes place. The function of ileum is mainly to absorb VitaminB12 & bile salts. Ref: Guyton,11e
Stomach
Duodenum and proximal jejunum
Large intestine
Ileum
G.I.T