They form as a result of increased pressure in the gallbladder and recurrent damage to the wall of the gallbladder.

Rokitansky–Aschoff sinuses, also entrapped epithelial crypts, are pseudodiverticula or pockets in the wall of the gallbladder. They may be microscopic or macroscopic.

Histologically, they are outpouchings of gallbladder mucosa into the gallbladder muscle layer and subserosal tissue as a result of hyperplasia and herniation of epithelial cells through the fibromuscular layer of the gallbladder wall. They are usually referred to as adenomyomatosis.

They are not of themselves considered abnormal, but they can be associated with cholecystitis.

Pain is the most common presenting symptom. It is usually described as sharp right upper quadrant pain that radiates to the right shoulder, or less commonly, behind the breastbone. Nausea and vomiting can be associated with biliary colic. Individuals may also present with pain that is induced following a fatty meal and the symptom of indigestion. The pain often lasts longer than 30 minutes, up to a few hours.

Patients usually have normal vital signs with biliary colic, whereas patients with cholecystitis are usually febrile and more ill appearing. Lab studies that should be ordered include a complete blood count, liver function tests and lipase. In biliary colic, lab findings are usually within normal limits. Alanine aminotransferase and aspartate transaminase are usually suggestive of liver disease whereas elevation of bilirubin and alkaline phosphatase suggests common bile duct obstruction. Pancreatitis should be considered if the lipase value is elevated; gallstone disease is the major cause of pancreatitis.

Biliary injury (bile duct injury) is the traumatic damage of the bile ducts. It is most commonly an iatrogenic complication of cholecystectomy — surgical removal of gall bladder, but can also be caused by other operations or by major trauma. The risk of biliary injury is more during laparoscopic cholecystectomy than during open cholecystectomy. Biliary injury may lead to several complications and may even cause death if not diagnosed in time and managed properly. Ideally biliary injury should be managed at a center with facilities and expertise in endoscopy, radiology and surgery.

An enterolith is a mineral concretion or calculus formed anywhere in the gastrointestinal system. Enteroliths are uncommon and usually incidental findings but, once found, they require at a minimum watchful waiting. If there is evidence of complications, they must be removed.

An enterolith may form around a "nidus", a small foreign object such as a seed, pebble, or piece of twine, that serves as an irritant. In this respect, an enterolith forms by a process similar to the creation of a pearl.

An enterolith is not to be confused with a gastrolith, which helps digestion.

In humans, enteroliths are rare and may be difficult to distinguish from gall stones. Their chemical composition is diverse, and rarely can a nidus be found. A differential diagnosis of an enterolith requires the enterolith, a normal gallbladder, and a diverticulum.

An enterolith typically forms within a diverticulum. An enterolith formed in a Meckel's diverticulum sometimes is known as a Meckel's enterolith. Improper use of magnesium oxide as a "long-term" laxative has been reported to cause enteroliths and/or medication bezoars.

Most enteroliths are not apparent and cause no complications. However, any complications that do occur are likely to be severe. Of these, bowel obstruction is most common, followed by ileus and perforation. Bowel obstruction and ileus typically occur when a large enterolith is expelled from a diverticulum into the lumen. Perforation typically occurs within the diverticulum.

Most human enteroliths are radiolucent on plain X-rays. They sometimes can be visualized on CT scans without contrast; presence of contrast in the lumen may reveal the enterolith as a void. Most often, they are visualized using ultrasound.

Although recent surveys of enterolith composition are lacking, one early review notes struvite (as in equines), calcium phosphate, and calcium carbonate and reports choleic acid. Deoxycholic acid and cholic acid have also been reported.

If fecal matter passes through the fistula into the bladder, the existence of the fistula may be revealed by pneumaturia or fecaluria.

Biliary colic, also known as a gallbladder attack or gallstone attack, is when pain occurs due to a gallstone temporarily blocking the bile duct. Typically, the pain is in the right upper part of the abdomen, and it can radiate to the shoulder. Pain usually lasts from one to a few hours. Often, it occurs after eating a heavy meal, or during the night. Repeated attacks are common.

Gallstone formation occurs from the precipitation of crystals that aggregate to form stones. The most common form is cholesterol gallstones. Other forms include calcium, bilirubin, pigment, and mixed gallstones. Other conditions that produce similar symptoms include appendicitis, stomach ulcers, pancreatitis, and gastroesophageal reflux disease.

Treatment for gallbladder attacks is typically surgery to remove the gallbladder. This can be either done through small incisions or through a single larger incision. Open surgery through a larger incision is associated with more complications than surgery through small incisions. Surgery is typically done under general anesthesia. In those who are unable to have surgery, medication to try to dissolve the stones or shock wave lithotripsy may be tried. , it is not clear whether surgery is indicated for everyone with biliary colic.

In the developed world, 10-15% of adults have gallstones. Of those with gallstones, biliary colic occurs in 1–4% each year. Nearly 30% of people have further problems related to gallstones in the year following an attack. About 15% of people with biliary colic eventually develop inflammation of the gallbladder if not treated. Other complications include inflammation of the pancreas.

A fistula involving the bladder can have one of many specific names, describing the specific location of its outlet:

- Bladder and intestine: "vesicoenteric", "enterovesical", or "vesicointestinal"

- Bladder and colon: "vesicocolic" or "colovesical"

- Bladder and rectum: "vesicorectal" or "rectovesical"

Early symptoms mimic gallbladder inflammation due to gallstones. Later, the symptoms may be that of biliary and stomach obstruction.

Of note, Courvoisier's law states that in the presence of a palpably enlarged gallbladder which is nontender and accompanied with mild painless jaundice, the cause is unlikely to be gallstones. This implicates possible malignancy of the gallbladder or pancreas, and the swelling is unlikely due to gallstones due to the chronic inflammation association with gallstones leading to a shunken, non-distensible gallbladder. However, Ludwig Georg Courvoisier's original observations, published in Germany in 1890, were not originally cited as a 'law', and no mention of malignancy or pain (tenderness) was made. These points are commonly missquoted or confused in the medical literature.

Calculi are usually asymptomatic, and large calculi may have required many years to grow to their large size.

Duodenal cancer is a cancer in the beginning section of the small intestine. It is relatively rare compared to gastric cancer and colorectal cancer. Its histology is usually adenocarcinoma.

Familial adenomatous polyposis (FAP), Gardner syndrome, Lynch syndrome, Muir–Torre syndrome, celiac disease, Peutz–Jeghers syndrome, Crohn's disease and juvenile polyposis syndrome are risk factors for developing this cancer.

The duodenum is the first part of the small intestine. It is located between the stomach and the jejunum. After foods combine with stomach acid, they descend into the duodenum where they mix with bile from the gallbladder and digestive juices from the pancreas.

The size of oral mucoceles vary from 1 mm to several centimeters and they usually are slightly transparent with a blue tinge. On palpation, mucoceles may appear fluctuant but can also be firm. Their duration lasts from days to years, and may have recurrent swelling with occasional rupturing of its contents.

Functional disorders of the gallbladder, bile duct and pancreas have been defined and classified by the Rome criteria for functional gastrointestinal disorders. The criteria outline three variants of functional disorders of the gallbladder, bile duct and pancreas, termed "functional gallbladder disorder", "functional biliary sphincter of Oddi disorder" and "functional pancreatic sphincter of Oddi disorder". All of the following criteria need to be met for as part of the definition of a functional disorder of the gallbladder:

- the pain must be located in the upper part of the abdomen and/or the right upper quadrant of the abdomen

- episodes of pain must last at least 30 minutes

- the symptoms must be recurrent, and occur at differing intervals

- the pain must incrementally increase to a "steady level"

- the pain must be severe enough the patient's daily activities are affected, or that the patient must attend the emergency department

- the pain must not be relieved by any of bowel movements, change in posture, or antacids; and,

- other structural disorders that could explain the symptoms must be excluded.

Individuals are classified as having a functional gallbladder disorder if the above criteria are met, if the gallbladder is present, and if the testing of liver enzymes, conjugated bilirubin, and pancreatic enzymes (amylase and lipase) are normal.

The classic manifestation of bladder exstrophy presents with:

- A defect in the abdominal wall occupied by both the exstrophied bladder as well as a portion of the urethra

- A flattened puborectal sling

- Separation of the pubic symphysis

- Shortening of a pubic rami

- External rotation of the pelvis.

Females frequently have a displaced and narrowed vaginal orifice, a clitoris, and divergent labia.

A calculus (plural calculi), often called a stone, is a concretion of material, usually mineral salts, that forms in an organ or duct of the body. Formation of calculi is known as lithiasis (). Stones can cause a number of medical conditions.

Some common principles (below) apply to stones at any location, but for specifics see the particular stone type in question.

Calculi are not to be confused with gastroliths.

The cancerous mass tends to block food from getting to the small intestine. If food cannot get to the intestines, it will cause pain, acid reflux, and weight loss because the food cannot get to where it is supposed to be processed and absorbed by the body.

Patients with duodenal cancer may experience abdominal pain, weight loss, nausea, vomiting, and chronic GI bleeding.

The condition affects all major structures within the thorax and abdomen. Generally, the organs are simply transposed through the sagittal plane. The heart is located on the right side of the thorax, the stomach and spleen on the right side of the abdomen and the liver and gall bladder on the left side. The heart's normal right atrium occurs on the left, and the left atrium is on the right. The lung anatomy is reversed and the left lung has three lobes while the right lung has two lobes. The intestines and other internal structures are also reversed from the normal, and the blood vessels, nerves, and lymphatics are also transposed.

If the heart is swapped to the right side of the thorax, it is known as "situs inversus with dextrocardia" or "situs inversus totalis". If the heart remains on the normal left side of the thorax, a much more rare condition (1 in 2,000,000 of the general population), it is known as "situs inversus with levocardia" or "situs inversus incompletus".

Situs inversus of the optic disc may occur unilaterally or bilaterally, associated with reduced binocularity and stereoacuity resembling monofixation syndrome. It is characterized by emergence of the retinal vessels in an anomalous direction (from the nasal rather than the temporal aspect) with dysversion (tilt) of the optic disc.

An adipose tissue neoplasm is a neoplasm derived from adipose tissue.

An example is lipoma.

The most common location to find a mucocele is the inner surface of the lower lip. It can also be found on the inner side of the cheek (known as the buccal mucosa), on the anterior ventral tongue, and the floor of the mouth. When found on the floor of the mouth, the mucocele is referred to as a ranula. They are rarely found on the upper lip. As their name suggests they are basically mucus lined cysts and they can also occur in the Paranasal sinuses most commonly the frontal sinuses, the frontoethmoidal region and also in the maxillary sinus. Sphenoid sinus involvement is extremely rare.

When the lumen of the vermiform appendix gets blocked due to any factor, again a mucocele can form.

Gallbladder cancer is a relatively uncommon cancer. It has peculiar geographical distribution being common in central and South America, central and eastern Europe, Japan and northern India; it is also common in certain ethnic groups e.g. Native American Indians and Hispanics. If it is diagnosed early enough, it can be cured by removing the gallbladder, part of the liver and associated lymph nodes. Most often it is found after symptoms such as abdominal pain, jaundice and vomiting occur, and it has spread to other organs such as the liver.

It is a rare cancer that is thought to be related to gallstones building up, which also can lead to calcification of the gallbladder, a condition known as porcelain gallbladder. Porcelain gallbladder is also rare. Some studies indicate that people with porcelain gallbladder have a high risk of developing gallbladder cancer, but other studies question this. The outlook is poor for recovery if the cancer is found after symptoms have started to occur, with a 5-year survival rate close to 3%.

In the absence of congenital heart defects, individuals with situs inversus are phenotypically normal, and can live normal healthy lives, without any complications related to their medical condition. There is a 5–10% prevalence of congenital heart disease in individuals with situs inversus totalis, most commonly transposition of the great vessels. The incidence of congenital heart disease is 95% in situs inversus with levocardia.

Many people with situs inversus totalis are unaware of their unusual anatomy until they seek medical attention for an unrelated condition, such as a rib fracture or a bout of appendicitis. The condition may also be discovered during the administration of certain medicines or during tests such as a Barium meal or enema. The reversal of the organs may then lead to some confusion, as many signs and symptoms will be on the atypical side. For example, if an individual with situs inversus develops appendicitis, they will present to the physician with lower left abdominal pain, since that is where their appendix lies. Thus, in the event of a medical problem, the knowledge that the individual has situs inversus can expedite diagnosis. People with this rare condition should inform their doctors before an examination, so the doctor can redirect their search for heart sounds and other signs. Wearing a medical identification tag can help inform health care providers in the event the person is unable to communicate.

Situs inversus also complicates organ transplantation operations as donor organs will more likely come from situs solitus (normal) donors. As hearts and livers are chiral, geometric problems arise placing an organ into a cavity shaped in the mirror image. For example, a person with situs inversus who requires a heart transplant needs all the vessels to the transplant donor heart reattached to their existing ones. However, the orientation of these vessels in a person with situs inversus is reversed, necessitating steps so that the blood vessels join properly.

Bladder exstrophy (also known as ectopia vesicae) is a congenital anomaly that exists along the spectrum of the exstrophy-epispadias complex and most notably involves protrusion of the urinary bladder through a defect in the abdominal wall. Its presentation is variable, often including abnormalities of the bony pelvis, pelvic floor, and genitalia. The underlying embryologic mechanism leading to bladder exstrophy is unknown, though it is thought to be in part due to failed reinforcement of the cloacal membrane by underlying mesoderm.

Colic (from Greek κολικός "kolikos", "relative to the colon") or cholic is a form of pain that starts and stops abruptly. It occurs due to muscular contractions of a hollow tube (colon, ureter, gall bladder, etc.) in an attempt to relieve an obstruction by forcing content out. It may be accompanied by vomiting and sweating. Types include:

- Baby colic, a condition, usually in infants, characterized by incessant crying

- Renal colic, a pain in the flank, characteristic of kidney stones

- Biliary colic, blockage by a gallstone of the common bile duct or cystic duct

- Horse colic, a potentially fatal condition experienced by horses, caused by intestinal displacement or blockage

- Devon colic, an affliction caused by lead poisoning

- Painter's colic or lead poisoning