Phân đen (Melaena)

Mô tả: Black, tarry, offensive-smelling stools.

Nguyên nhân: • Gastrointestinal haemorrhagebleed More common • Peptic ulcer disease • Oesophageal varices • Oesophagitis • Gastritis Less common • Mallory–Weiss tear • Neoplasm

Cơ chế: Bleeding from any cause in the upper gastrointestinal tract. It is often stated that the bleeding must be above the ligament of treitz; however, this is not always the case. The black, foul-smelling nature of the stool is due to the oxidation of iron from the haemoglobin, as it descends through the gastrointestinal tract.

Ý nghĩa lâm sàng: If present, melaena demands full investigation, bearing in mind that it is not necessarily specific to the location of the bleed.