A bile duct is any of a number of long tube-like structures that carry bile.
Bile, required for the digestion of food, is excreted by the liver into passages that carry bile toward the hepatic duct, which joins with the cystic duct (carrying bile to and from the gallbladder) to form the common bile duct, which opens into the intestine.
The biliary tree (see below) is the whole network of various sized ducts branching through the liver.
The path is as follows: Bile canaliculi → Canals of Hering → interlobular bile ducts → intrahepatic bile ducts → left and right hepatic ducts merge to form → common hepatic duct exits liver and joins → cystic duct (from gall bladder) forming → common bile duct → joins with pancreatic duct → forming ampulla of Vater → enters duodenum
Common bile duct
The top half of the common bile duct is associated with the liver, while the bottom half of the common bile duct is associated with the pancreas, through which it passes on its way to the intestine. It opens in the part of the intestine called the duodenum into a structure called the ampulla of Vater.
Blockage of the bile duct by a cancer, gallstones, or scarring read more [...]
Belching, also known as burping, ructus, or eructation, involves the release of gas from the digestive tract (mainly esophagus and stomach) through the mouth. It is usually accompanied with a typical sound and, at times, an odor.
Belching is typically caused by swallowing air (aerophagia) when eating or drinking and subsequently expelling it, so in this case the expelled gas is mainly a mixture of nitrogen and oxygen. Burps can also be caused by drinking carbonated drinks such as beer, soft drinks, or champagne, in which case the expelled gas is carbon dioxide from the drink itself. Common diabetes drugs metformin  and Byetta  can cause belching, especially at higher doses. This often resolves in a few weeks. Belching combined with other symptoms such as dyspepsia, nausea and heartburn may be a sign of an ulcer or hiatal hernia, and should be reviewed by a physician. 
The sound of burping is caused by the vibration of the upper esophageal sphincter as the gas passes through it. The current Guinness world record for the loudest burp is 118.1 dB, set by Paul Hunn from London, England in 2000. (This would be noticeably louder than a chainsaw at a distance of read more [...]
Appendicitis (or epityphlitis) is a condition characterized by inflammation of the appendix. All cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of peritonitis and shock. Reginald Fitz first described acute appendicitis in 1886, and it has been recognized as one of the most common causes of severe acute abdominal pain worldwide.
Causes of Appendicitis
Location of the appendix in the digestive system
On the basis of experimental evidence, acute appendicitis seems to be the end result of a primary obstruction of the appendix lumen. Once this obstruction occurs the appendix subsequently becomes filled with mucus and swells, increasing pressures within the lumen and the walls of the appendix, resulting in thrombosis and occlusion of the small vessels, and stasis of lymphatic flow. Rarely, spontaneous recovery can occur at this point. As the former progresses, the appendix becomes ischemic and then necrotic. As bacteria begin to leak out through the dying walls, pus forms within and around the appendix (suppuration). The end result of this cascade is appendiceal rupture read more [...]
Crohn’s disease is a disease of the digestive system which may affect any part of the gastrointestinal tract from mouth to anus. As a result, the symptoms of Crohn’s disease can vary significantly among afflicted individuals. The main gastrointestinal symptoms are abdominal pain, diarrhea (which may be visibly bloody), vomiting, or weight loss. Crohn’s disease can also cause complications outside of the gastrointestinal tract such as skin rashes, arthritis, and inflammation of the eye.
The precise cause of Crohn’s disease is not known. The disease occurs when the immune system attacks the gastrointestinal tract and for this reason, Crohn’s disease is considered an autoimmune disease. This autoimmune activity produces inflammation in the gastrointestinal tract, and therefore Crohn’s disease is classified as an inflammatory bowel disease.
Like many other autoimmune diseases, Crohn’s disease is believed to be genetically linked. The highest risk occurs in individuals with siblings who have the disease. Males and females are equally affected. Smokers are three times more likely to develop Crohn’s disease. Crohn disease affects between 400,000 and 600,000 read more [...]
Cholecystitis is inflammation of the gall bladder.
Causes and pathology of Cholecystitis
Cholecystitis is often caused by cholelithiasis (the presence of choleliths, or gallstones, in the gallbladder), with choleliths most commonly blocking the cystic duct directly. This leads to inspissation of bile, bile stasis, and secondary infection by gut organisms, predominantly E coli and Bacteroides species.
The gallbladder’s wall becomes inflamed. Extreme cases may result in necrosis and rupture. Inflammation often spreads to its outer covering, thus irritating surrounding structures such as the diaphragm and bowel.
Less commonly, in debilitated and trauma patients, the gallbladder may become inflamed and infected in the absence of cholelithiasis, and is known as acute acalculous cholecystitis.
Stones in the gallbladder may not cause obstruction and the accompanying acute attack. The patient might develop a chronic, low-level inflammation which leads to a chronic cholecystitis, where the gallbladder is fibrotic and calcified.
Symptoms of Cholecystitis
Cholecystitis usually presents as a pain in the right upper quadrant. This is usually a constant, severe pain. The pain read more [...]
In medicine, gallstones (choleliths) are crystalline bodies formed within the body by accretion or concretion of normal or abnormal bile component.
Gallstones can occur anywhere within the biliary tree, including the gallbladder and the common bile duct. Obstruction of the common bile duct is choledocholithiasis; obstruction of the biliary tree can cause jaundice; obstruction of the outlet of the pancreatic exocrine system can cause pancreatitis. Cholelithiasis is the presence of stones in the gallbladder—chole- means “bile”, lithia means “stone”, and -sis means “process”.
The characteristics of gallstones are various. Independent of appearance, however, gallstones from animals are valuable on the market.
Characteristics of Gallstone
A gallstone’s size varies and may be as small as a sand grain or as large as a golf ball. The gallbladder may develop a single, often large, stone or many smaller ones. They may occur in any part of the biliary system.
Gallstones have different appearance, depending on their contents. On the basis of their contents, gallstones can be subdivided into the two following types:
read more [...]
Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrous scar tissue as well as regenerative nodules (lumps that occur as a result of a process in which damaged tissue is regenerated), leading to progressive loss of liver function. Cirrhosis is most commonly caused by alcoholism and hepatitis C, but has many other possible causes.
Ascites (fluid retention in the abdominal cavity) is the most common complication of cirrhosis and is associated with a poor quality of life, increased risk of infection, and a poor long-term outcome. Other potentially life-threatening complications are hepatic encephalopathy (confusion and coma) and bleeding from esophageal varices. Cirrhosis is generally irreversible once it occurs, and treatment generally focuses on preventing progression and complications. In advanced stages of cirrhosis the only option is a liver transplant.
The word “cirrhosis” derives from Greek kirrhos, meaning “tawny” (the orange-yellow colour of the diseased liver). While the clinical entity was known before, it was René Laennec who gave it the name “cirrhosis” in his 1819 work in which read more [...]
Hepatitis (plural hepatitides) implies injury to the liver characterized by the presence of inflammatory cells in the tissue of the organ. The name is from ancient Greek hepar (ηπαρ) or hepato– (ηπατο-), meaning liver, and suffix -itis, meaning “inflammation” (c. 1727). The condition can be self-limiting, healing on its own, or can progress to scarring of the liver. Hepatitis is acute when it lasts less than six months and chronic when it persists longer. A group of viruses known as the hepatitis viruses cause most cases of liver damage worldwide. Hepatitis can also be due to toxins (notably alcohol), other infections or from autoimmune process. It may run a subclinical course when the affected person may not feel ill. The patient becomes unwell and symptomatic when the disease impairs liver functions that include, among other things, removal of harmful substances, regulation of blood composition, and production of bile to help digestion.
Causes of Hepatitis
Viral Hepatitis: Hepatitis A through E (more than 95% of viral cause), Herpes simplex, Cytomegalovirus, Epstein-Barr, yellow fever virus, adenoviruses.
Non viral infection: toxoplasma, read more [...]
An anal fistula is an abnormal connection between the epithelialised surface of the anal canal and (usually) the perianal skin.
Anal fistulae originate from the anal glands, which are located between the two layers of the anal sphincters and which drain into the anal canal. If the outlet of these glands becomes blocked, an abscess can form which can eventually point to the skin surface. The tract formed by this process is the fistula.
Abscesses can recur if the fistula seals over, allowing the accumulation of pus. It then points to the surface again, and the process repeats.
Anal fistulas per se do not generally harm and they often do not hurt, but they can be irritating because of the pus-drain (and, it is not unknown for formed stools to be passed through the fistula); additionally, recurrent abscesses may lead to significant short term morbidity from pain, and create a nidus for systemic spread of infection.
Surgery is considered essential in the decompression of acute abscesses; repair of the fistula itself is considered an elective procedure which many patients elect to undertake due to the discomfort and inconvenience associated with a draining tract.
Symptoms of read more [...]
An anal fissure is an unnatural crack or tear in the anus skin. As a fissure, these tiny tears may show as bright red rectal bleeding and cause severe periodic pain after defecation. The tear usually extends from the anal opening and located posteriorly in the midline. This location is probably because of the relatively unsupported nature of the anal wall in that location.
Causes of Anal fissure
Most anal fissures are caused by stretching of the anal mucosa beyond its capability. Many acute anal fissures will heal spontaneously. Some fissures become chronic and will not heal. The most common cause for this is spasm of the internal anal sphincter muscle. This spasm causes poor blood flow to the anal mucosa, hence producing an ulcer which does not heal since it is deprived of normal blood supply.
Anal fissures are common in women after childbirth, excessive anal intercourse, after difficult bowel movements and in infants following constipation.
Prevention for Anal fissure
In infants under one year old, frequent nappy/diaper change can prevent anal fissure. For adults, the following can help prevent fissure:
Treating constipation by eating food rich in dietary read more [...]