Bladder stones are small mineral deposits that can form in the bladder. In most cases bladder stones develop when the urine becomes very concentrated or when one is dehydrated. This allows for minerals, such as calcium or magnesium salts, to crystallize and form stones. Bladder stones vary in number, size and consistency. In some cases bladder stones do not cause any symptoms and are discovered as an incidental finding on a plain radiograph. However, when symptoms do occur, these may include severe lower abdominal and back pain, difficult urination, frequent urination at night, fever, painful urination and blood in the urine. The majority of individuals who are symptomatic will complain of pain which comes in waves. The pain may also be associated with nausea, vomiting and chills.

Bladder stones vary in their size, shape and texture- some are small, hard and smooth whereas others are huge, spiked and very soft. One can have one or multiple stones. Bladder stones are somewhat more common in men who have prostate enlargement. The large prostate presses on the urethra and makes it difficult to pass urine. Over time, stagnant urine collects in the bladder and minerals like calcium start to precipitate. Other individuals who develop bladder stones include those who have had spinal cord injury, paralysis, or some type of nerve damage. When nerves to the back are damaged, the bladder cannot empty, resulting in stagnant urine.

Most patients have symptoms in the first year of life. It is rare for symptoms to be undetected until adulthood, and usually adults have associated complications. The classic triad of intermittent abdominal pain, jaundice, and a right upper quadrant abdominal mass is found only in minority of patients.

In infants, choledochal cysts usually lead to obstruction of the bile ducts and retention of bile. This leads to jaundice and an enlarged liver. If the obstruction is not relieved, permanent damage may occur to the liver - scarring and cirrhosis - with the signs of portal hypertension (obstruction to the flow of blood through the liver) and ascites (fluid accumulation in the abdomen). There is an increased risk of cancer in the wall of the cyst.

In older individuals, choledochal cysts are more likely to cause abdominal pain and intermittent episodes of jaundice and occasionally cholangitis (inflammation within the bile ducts caused by the spread of bacteria from the intestine into the bile ducts). Pancreatitis also may occur. The cause of these complications may be related to either abnormal flow of bile within the ducts or the presence of gallstones

Urethral diverticula are often asymptomatic and symptoms that are present tend to be nonspecific. They can co-occur with cancer, in approximately 6-9% of cases, most commonly adenocarcinoma, but also including squamous cell carcinoma and transitional cell carcinoma. Approximately 10% of cases co-occur with kidney stones.

There are 2 types of urethral diverticulums. Congenital and acquired. In infancy usually the urethral diverticulum is congenital but in rare instances acquired urethral diverticulum can be seen in infancy specially following traumatic catheterization.

Common symptoms of urethral diverticulum include incontinence, urinary frequency and urgency, pain during sex, and pain during urination. Other symptoms include pain localized to the urethra or pelvis and frequent urinary tract infection.

When urethral diverticulum becomes severe, a painful mass can sometimes be felt inside the introitus of the vagina, which can discharge pus. If the mass is hard or bleeds, complications like cancer or kidney stones may be present.

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

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.

Diverticula are described as being true or false depending upon the layers involved:

- True diverticula involve all layers of the structure, including muscularis propria and adventitia, such as Meckel's diverticulum.

- False diverticula (also known as "pseudodiverticula") do not involve muscular layers or adventitia. False diverticula, in the GI tract for instance, involve only the submucosa and mucosa.

Choledochal cysts (a.k.a. bile duct cyst) are congenital conditions involving cystic dilatation of bile ducts. They are uncommon in western countries but not as rare in East Asian nations like Japan and China.

Most children with vesicoureteral reflux are asymptomatic. Vesicoureteral reflux may be diagnosed as a result of further evaluation of dilation of the kidney or ureters draining urine from the kidney while in utero as well as when a sibling has VUR (though routine testing in either circumstance is controversial). Reflux also increases risk of acute bladder and kidney infections, so testing for reflux may be performed after a child has one or more infections.

In infants, the signs and symptoms of a urinary tract infection may include only fever and lethargy, with poor appetite and sometimes foul-smelling urine, while older children typically present with discomfort or pain with urination and frequent urination.

Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into the ureters/kidneys. Urine normally travels in one direction (forward, or anterograde) from the kidneys to the bladder via the ureters, with a 1-way valve at the vesicoureteral (ureteral-bladder) junction preventing backflow. The valve is formed by oblique tunneling of the distal ureter through the wall of the bladder, creating a short length of ureter (1–2 cm) that can be compressed as the bladder fills. Reflux occurs if the ureter enters the bladder without sufficient tunneling, i.e., too "end-on".

Guttural pouch: A large (300-500 ml), paired, air-filled ventral diverticulum of the auditory tube found in horses and other Perissodactyla.

Jackstone calculi are rare bladder stones that have an appearance resembling toy jacks. They are almost always composed of calcium oxalate dihydrate and consist of a dense central core and radiating . They are typically light brown with dark patches and are usually formed in the urinary bladder and rarely in the upper urinary tract. Their appearance on plain radiographs and computed tomography in human patients is usually easily recognizable. Jackstones often must be removed via cystolithotomy.

A urethral diverticulum is a condition where the urethra or the periurethral glands push into the connective tissue layers (fascia) that surround it.

The term is derived from the Greek words "sialon" (saliva) and "lithos" (stone), and the Latin "-iasis" meaning "process" or "morbid condition". A "calculus" (plural "calculi") is a hard, stone-like concretion that forms within an organ or duct inside the body. They are usually made from mineral salts, and other types of calculi include tonsiloliths (tonsil stones) and renal calculi (kidney stones). "Sialolithiasis" refers to the formation of calculi within a salivary gland. If a calculus forms in the duct that drains the saliva from a salivary gland into the mouth, then saliva will be trapped in the gland. This may cause painful swelling and inflammation of the gland. Inflammation of a salivary gland is termed "sialadenitis". Inflammation associated with blockage of the duct is sometimes termed "obstructive sialadenitis". Because saliva is stimulated to flow more with the thought, sight or smell of food, or with chewing, pain and swelling will often get suddenly worse just before and during a meal ("peri-prandial"), and then slowly decrease after eating, this is termed "meal time syndrome". However, calculi are not the only reasons that a salivary gland may become blocked and give rise to the meal time syndrome. Obstructive salivary gland disease, or obstructive sialadenitis, may also occur due to fibromucinous plugs, duct stenosis, foreign bodies, anatomic variations, or malformations of the duct system leading to a mechanical obstruction associated with stasis of saliva in the duct.

Salivary stones may be divided according to which gland they form in. About 85% of stones occur in the submandibular gland, and between 5-10% occur in the parotid gland. In about 0-5% of cases, the sublingual gland or a minor salivary gland is affected. When minor glands are rarely involved, caliculi are more likely in the minor glands of the buccal mucosa and the maxillary labial mucosa. Submandibular stones are further classified as anterior or posterior in relation to an imaginary transverse line drawn between the mandibular first molar teeth. Stones may be radiopaque, i.e. they will show up on conventional radiographs, or radiolucent, where they not be visible on radiographs (although some of their effects on the gland may still be visible). They may also symptomatic or asymptomatic, according to whether they cause any problems or not.

Signs and symptoms are variable and depend largely upon whether the obstruction of the duct is complete or partial, and how much resultant pressure is created within the gland. The development of infection in the gland also influences the signs and symptoms.

- Pain, which is intermittent, and may suddenly get worse before mealtimes, and then slowly get better (partial obstruction).

- Swelling of the gland, also usually intermittent, often suddenly appearing or increasing before mealtimes, and then slowly going down (partial obstruction).

- Tenderness of the involved gland.

- Palpable hard lump, if the stone is located near the end of the duct. If the stone is near the submandibular duct orifice, the lump may be felt under the tongue.

- Lack of saliva coming from the duct (total obstruction).

- Erythema (redness) of the floor of the mouth (infection).

- Pus discharging from the duct (infection).

- Cervical lymphadenitis (infection).

- Bad Breath.

Rarely, when stones form in the minor salivary glands, there is usually only slight local swelling in the form of a small nodule and tenderness.

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"

Bladder rupture (rupture of bladder, ) may occur if the bladder is overfilled and not emptied. This can occur in the case of binge drinkers who have consumed large quantities of fluids, but are not conscious of the need to urinate due to stupor. This condition is very rare in women, but does occur. Signs and symptoms include localized pain and uraemia (poisoning due to reabsorbed waste).

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.

Bladder tamponade is obstruction of the bladder outlet due to heavy blood clot formation within it. It generally requires surgery. Such heavy bleeding is usually due to bladder cancer.

A vesicointestinal fistula (or intestinovesical fistula) is a form of fistula between the bladder and the bowel.

The majority of people with a Meckel's diverticulum are asymptomatic. An asymptomatic Meckel's diverticulum is called a "silent" Meckel's diverticulum. If symptoms do occur, they typically appear before the age of two years.

The most common presenting symptom is painless rectal bleeding such as melaena-like black offensive stools, followed by intestinal obstruction, volvulus and intussusception. Occasionally, Meckel's diverticulitis may present with all the features of acute appendicitis. Also, severe pain in the epigastric region is experienced by the patient along with bloating in the epigastric and umbilical regions. At times, the symptoms are so painful that they may cause sleepless nights with acute pain felt in the foregut region, specifically in the epigastric and umbilical regions.

In some cases, bleeding occurs without warning and may stop spontaneously. The symptoms can be extremely painful, often mistaken as just stomach pain resulting from not eating or constipation.

Rarely, a Meckel's diverticulum containing ectopic pancreatic tissue can present with abdominal pain and increased serum amylase levels, mimicking acute pancreatitis.

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.

A salivary gland fistula (plural "fistulae") is a fistula (i.e. an abnormal, epithelial-lined tract) involving a salivary gland or duct.

Salivary gland fistulae are almost always related to the parotid gland or duct, although the submandibular gland is rarely the origin.

The fistula can communicate with the mouth (usually causing no symptoms), the paranasal sinuses (giving rhinorrhea) or the facial skin (causing saliva to drain onto the skin).

The usual cause is trauma, however salivary fistula can occur as a complication of surgery, or if the duct becomes obstructed with a calculus.

Most parotid fistulae heal by themselves within a few weeks.

Inflammation of the diverticulum can mimic symptoms of appendicitis, i.e., periumbilical tenderness and intermittent crampy abdominal pain. Perforation of the inflamed diverticulum can result in peritonitis. Diverticulitis can also cause adhesions, leading to intestinal obstruction.

Diverticulitis may result from:

- Association with the mesodiverticular band attaching to the diverticulum tip where torsion has occurred, causing inflammation and ischaemia.

- Peptic ulceration resulting from ectopic gastric mucosa of the diverticulum

- Following perforation by trauma or ingested foreign material e.g. stalk of vegetable, seeds or fish/chicken bone that become lodged in Meckel's diverticulum.

- Luminal obstruction due to tumors, enterolith, foreign body, causing stasis or bacterial infection.

- Association with acute appendicitis

The hallmark of a stone that obstructs the ureter or renal pelvis is excruciating, intermittent pain that radiates from the flank to the groin or to the inner thigh. This pain, known as renal colic, is often described as one of the strongest pain sensations known. Renal colic caused by kidney stones is commonly accompanied by urinary urgency, restlessness, hematuria, sweating, nausea, and vomiting. It typically comes in waves lasting 20 to 60 minutes caused by peristaltic contractions of the ureter as it attempts to expel the stone.

The embryological link between the urinary tract, the genital system, and the gastrointestinal tract is the basis of the radiation of pain to the gonads, as well as the nausea and vomiting that are also common in urolithiasis. Postrenal azotemia and hydronephrosis can be observed following the obstruction of urine flow through one or both ureters.

Pain in the lower left quadrant can sometimes be confused with diverticulitis because the sigmoid colon overlaps the ureter and the exact location of the pain may be difficult to isolate due to the close proximity of these two structures.

A Gartner's duct cyst (sometimes incorrectly referred to as "vaginal inclusion cyst") is a benign vaginal cystic lesion that arises from the Gartner's duct, which is a vestigial remnant of the mesonephric duct (wolffian duct) in females. They are typically small asymptomatic cysts that occur along the lateral walls of the vagina, following the course of the duct. They can present in adolescence with painful menstruation (Dysmenorrhea) or difficulty inserting a tampon. They can also enlarge to substantial proportions and be mistaken for urethral diverticulum or other structures.

There is a small association between Gartner's duct cysts and metanephric urinary anomalies, such as ectopic ureter & ipsilateral renal hypoplasia. Because of this, imaging is recommended before excision.