EsophagusCommonly called as food pipe, it is located in the neck, chest and abdomen. It is responsible for transporting food from throat to the stomachInitially considered as a mere conduit, recent understanding of the physiology of esophagus has resulted in better understanding of the numerous diseases affecting the esophagus.Symptoms of esophageal diseases include difficulty in swallowing food (dysphagia), pain while swallowing food (odynophagia), regurgitation, blood in vomiting (hematemesis), heart burn and respiratory problems.Common diseases affecting esophagus include reflux esophagitis, esophageal candidiasis, esophageal motility disorders (achalasia cardia, nutcracker esophagus and diffuse esophageal spasm), diverticulum and esophageal varices.

StomachOrgan located in the upper abdomen responsible for temporary storage and digestion of food. It has the capacity to expand and store large quantities of food. It also performs important immunological functions.Receptive relaxation and accommodative reflex (the ability to expand significantly to receive and store food) is unique to stomach.Symptoms of gastric diseases include upper abdominal pain, early satiety, dysphagia, blood in vomiting (hematemesis), heart burn, abdominal distention, blood in stools, loss of weight and appetiteCommon diseases affecting stomach include acid peptic disease, gastric ulcer, gastric varices and gastric neoplasms.

Small IntestineTubular organ located within the abdomen responsible numerous digestive and absorptive processes of food. It is called “small” intestine because of its smaller diameter when compared to the large intestine. The length of small intestine is many fold longer than large intestine. It comprises of duodenum, jejunum and ileum.Predominant site for digestion and absorption of carbohydrate, fat and protein occur in the small intestine.Symptoms include into abdominal pain, diarrhea, abdominal distention, vomiting, blood in stools, malnourishment, loss of weight and appetite.Common diseases include infection, ulcers, stricture, polyps and inflammation (inflammatory bowel disease). They can also be content of hernia.