ABSTRACT
This chapter presents some of diseases in gastrointestinal (GI) tract and its diagnostic methods. The myenteric plexus (of Auerbach) at the gastro-oesophageal junction (GOJ) degenerates, resulting in failure of GOJ relaxation. The stomach is the most common site for GI lymphoma, mostly non-Hodgkin (i.e. mucosa-associated lymphoid tissue lymphoma). It accounts for about 3" of gastric malignancies, either as a primary or direct invasion from an adjacent tumour. The GI tract is most commonly affected in patients with primary amyloidosis, typically the colon. GI malignancy affects the liver via the portal vein. The top three tumours that metastasise to the liver are colorectal, gastric and pancreatic. Zollinger–Ellison syndrome leads to increased production of gastric HCl. Budd–Chiari syndrome presents with hepatomegaly, ascites and classically paroxysmal nocturnal haemoglobinuria. Xanthogranulomatous cholecystitis (XGC) is an uncommon inflammatory disorder of the gall bladder characterised by multiple intramural nodules and proliferative fibrosis.
