Urology Care Foundation The Official Foundation of the American Urological Association

Urology Care Foundation The Official Foundation of the American Urological Association


Get the facts. And the help you need.
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Get the facts. And the help you need.

Urachal Abnormalities

Before birth, there is a connection between the bellybutton and the bladder. This connection, called the urachus, normally disappears before birth. But what happens if part of the urachus remains after birth? Read on to learn more about what problems can arise.

What happens under normal conditions?

The bladder, located in the lower abdomen, is formed from structures located in the lower half of the developing fetus that are directly connected to the umbilical cord. After the first few weeks of gestation, this thick pathway to and from the placenta contains blood vessels, a merged channel to the future intestine and a tubular structure called the allantois. The internal part of the allantois is connected to the top of the developing bladder, and in ordinary circumstances, collapses and becomes a cord-like structure called the urachus. The formation and regression of this connection from the top of the bladder to the bellybutton are completed by the middle of the second trimester of pregnancy (approximately 20 weeks).

Although the urachus is easily seen by a surgeon whenever an operation inside the abdomen or around the bladder is performed, it is a remnant of development that serves no further purpose but can be a source of specific health problems. Such problems are rare and usually seen in childhood, but occasionally can be seen for the first time in adults.

What are the symptoms of urachal abnormalities?

Because this remnant of early development is found between the bellybutton and the top of the bladder, diseases of the urachus can appear anywhere in that space. In newborns and infants, persistent drainage or "wetness" of the bellybutton can be a sign of an urachal problem. However, the most common detectable problem at the bellybutton is a granuloma, a reddened area that is present because the base of the umbilical cord stump did not heal properly.

Urachal abnormalities can also be seen without persistent umbilical drainage — 35 percent of urachal problems are manifestations of an enclosed urachal cyst or infected urachal cyst (abscess). This type of problem is seen more often in older children and adults. Instead of visible bellybutton drainage, the symptoms of such a cyst consist of lower abdominal pain, fever, a lump that can be felt, pain with urination, urinary tract infection or hematuria.

How are urachal abnormalities treated?

An umbilical granuloma is usually treated by chemical cauterization in the office of the primary care provider. The condition is a superficial abdominal wall problem that heals after treatment and has no long-term implications; it is not caused by an urachal problem.

In contrast to the simple granuloma, persistent umbilical wetness needs to be further evaluated. Approximately 65 percent of all urachal problems appear as a sinus or drainage opening at the bellybutton. Most of those are not connected all the way to the bladder, but a small percentage represents an open pathway from the bladder to bellybutton, called a patent urachus. The drainage can be analyzed for urea and creatinine levels, which would be high if the fluid was primarily made of urine from a bladder connection instead of inflammatory tissue fluid. There can be associated redness from the drainage itself. Skin infection – indicated by tenderness, fever or spreading redness of the surrounding skin – can occur and requires prompt antibiotic treatment and possible hospitalization. This is called omphalitis and can be caused by bacteria that have become involved with an urachal sinus or the other embryologic structure in the bellybutton that was once connected to the intestinal system and might also be persistent. Once inflammation is controlled, the nature and extent of an opening at the bellybutton can be determined by a sinogram. This involves placing a small tube into the sinus opening and allowing contrast material to flow in while taking X-rays to determine the direction and extent of the channel. If the channel follows the expected pathway toward the top of the bladder, the diagnosis is urachal sinus. Treatment should be directed toward complete surgical removal of the urachus and all of its connections, including a small amount of the top of the bladder. Leaving any portion of the structure allows for the possible development of a future malignancy. Less than 1 percent of all bladder malignancies occur in the urachus, but once the urachus has become a potential problem, it should be removed.

When there is no draining sinus to investigate, an ultrasound of the lower abdomen will show the typical findings of a fluid-filled, enclosed lump in the location of the urachus. In an adult, where the rare possibility of malignancy could be present, an abdominal and pelvic CT scan might be helpful. Again, complete removal of the urachus is important. Simple needle or other drainage of the cyst will result in recurrence in at least one-third of patients, since the linings and structures are still present. About 80 percent of infected cysts are populated by staphylococcus aureus, and one-third contains multiple types of bacteria. Almost all the time, such an infected cyst stays confined to its predetermined anatomical location; rarely, an infected cyst can drain into the peritoneal cavity and present with additional signs of peritonitis and febrile illness.

Therefore, most urachal problems can be characterized by the physical examination and a sinogram or ultrasound. Sometimes a combination of these is needed, and occasionally it is useful to obtain a voiding cystourethrogram. This is done when the draining urachus is associated with outlet obstruction of the bladder, which would also need to be treated. This possibility is usually determined by the age, gender and physical examination of the patient. There are also situations where a direct look inside the bladder (cystoscopy) can add a bit more information to the diagnostic picture, but most urologists recommend that the basic course of action be determined by the previously described approach.

What can be expected after treatment for urachal abnormalities?

After complete surgical removal of a troublesome urachus with no immediate postoperative problems, there should be no further issues and no need for follow-up or evaluation on a regular basis.

Frequently asked questions:

Besides the problems that have already been outlined, are there other diseases that appear at the bellybutton? 

As you might expect, there have been rare reports of other inflammatory problems involving the structures that are contained in the umbilical cord. These include infections of the remnant blood vessels. In addition, the vitelline duct, which is supposed to regress in its course between the bellybutton and the small intestine, sometimes has its own remnant problems. The sinogram that is useful for identifying urachal problems will also serve to identify a likely vitelline duct problem.

Occasionally, an intra-abdominal process such as appendicitis or ovarian cyst can mimic some of the symptoms of an urachal problem.

Are urachal abnormalities hereditary?

No. There is no evidence that they are inherited.

After my baby's umbilical cord stump came off, his bellybutton was extremely red. Is this normal or does he need immediate evaluation?

Some redness is expected after the stump falls away. Dabbing a small amount of alcohol on the site with a Q-tip twice a day will usually allow complete healing in two to three days. If the redness fails to improve or worsens, contact your primary care provider.

Reviewed January 2011

You are leaving UrologyHealth.org. The Urology Care Foundation has no control over the content of this site. Click OK to proceed.

Urology A - Z
  • no topics for this letter
  • no topics for this letter
  • no topics for this letter
  • no topics for this letter
  • no topics for this letter
  • no topics for this letter
  • no topics for this letter
Urachal Abnormalities Glossary
  • abdomen: Also referred to as the belly. It is the part of the body that contains all of the internal structures between the chest and the pelvis.

  • abdominal: in the abdomen, the cavity of this part of the body containing the stomach, intestines and bladder.

  • abscess: An accumulation of pus anywhere in the body.

  • allantois: A membranous sac that grows from the lower gut and it combines with the chorion to form the umbilical cord and placenta.

  • antibiotic: Drug that kills bacteria or prevents them from multiplying.

  • appendicitis: Swelling of the appendix causing severe pain.

  • bacteria: Single-celled microorganisms that can exist independently (free-living) or dependently upon another organism for life (parasite). They can cause infection and are usually treated with antibiotics.

  • bladder: The bladder is a thick muscular balloon-shaped pouch in which urine is stored before being discharged through the urethra.

  • cauterization: To seal a wound, or destroy abnormal or infected tissue, with a heated instrument, a laser, an electric current, or a caustic substance.

  • creatinine: A waste product from meat protein in the diet and from the muscles of the body. Creatinine is removed from blood by the kidneys; as kidney disease progresses, the level of creatine in the blood increases.

  • CT scan: Also known as computerized tomography, computerized axial tomography or CT scan. A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images of the body. Shows detailed images of any part of the body, including bones, muscles, fat and organs. CT scans are more detailed than general X-rays.

  • cyst: An abnormal sac containing gas, fluid or a semisolid material. Cysts may form in kidneys or other parts of the body.

  • cystoscopy: Also known as cystourethroscopy. An examination with a narrow, flexible tube-like instrument passed through the urethra to examine the bladder and urinary tract for structural abnormalities or obstructions, such as tumors or stones.

  • cystourethrogram: Also called a voiding cystogram. A specific X-ray that examines the urinary tract. A catheter (hollows tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body)and the bladder is filled with a liquid dye. X-ray images are taken as the bladder fills and empties. The X-rays will show if there is any reverse flow of urine into the ureters and kidneys.

  • cysts: Abnormal sacs containing gas, fluid or a semisolid material.

  • diagnosis: The process by which a doctor determines what disease or condition a patient has by studying the patient's symptoms and medical history, and analyzing any tests performed (e.g., blood tets, urine tests, brain scans, etc.).

  • embryo: A human offspring in the early stages following conception up to the end of the eighth week.

  • embryologic: Relating to or characteristic of an embryo, a human offspring in the early stages following conception up to the end of the eighth week.

  • embryologic: Pertaining to embryology, which is the study of the development of human offspring.

  • febrile: Relating to a fever.

  • fetus: An unborn offspring from the end of the eighth week of conception until birth.

  • gestation: The process of carrying offspring in the womb during pregnancy.

  • granuloma: A small mass of healing tissue caused by chronic infection.

  • hematuria: Blood in the urine, which can be a sign of a kidney stone or other urinary problem. Gross hematuria is blood that is visible to the naked eye. Microscopic hematuria cannot be seen but is detected on a urine test.

  • infection: A condition resulting from the presence of bacteria or other microorganisms.

  • inflammation: Swelling, redness, heat and/or pain produced in the area of the body as a result of irritation, injury or infection.

  • inflammatory: Characterized or caused by swelling, redness, heat and/or pain produced in an area of the body as a result of irritation, injury or infection.

  • intestine: The part of the digestive system between the stomach and the anus that digests and absorbs food and water.

  • ions: Electrically charged atoms.

  • malignancies: Cancerous growths.

  • malignancy: A cancerous growth.

  • obstruction: something that obstructs, blocks, or closes up with an obstacle

  • omphalitis: Inflammation of the umbilicus and surrounding parts.

  • ovarian: Relating to either of the two female reproductive organs that produce eggs.

  • ovarian cyst: The ovary will form a fluid-filled cyst on the surface of the ovary each month after an egg is released from the ovary during normal ovulation.

  • patent urachus: Unblocked urachus.

  • patent urachus: Unblocked urachus.

  • pelvic: Relating to, involving or located in or near the pelvis.

  • peritoneal cavity: The space enclosed by the peritoneum, the membrane that lines the cavity of the abdomen.

  • peritonitis: Inflammation of the membrane that lines the abdomen.

  • placenta: Organ that develops inside the uterus of a pregnant woman. Supplies the food and oxygen to the fetus through the umbilical cord and is expelled after birth.

  • postoperative: Occurring after a surgical operation.

  • pregnancy: The condition of being pregnant.

  • sinogram: Special X-ray procedure that is done with contrast dye to visualize any abnormal opening (sinus) in the body.

  • sinus: Abnormal opening. Elongated tract leading from pus-filled region of the body to the exterior or to the cavity of a hallow organ.

  • staphylococcus aureus: Bacteria commonly found on the skin of healthy people.

  • stent: With regard to treating ureteral stones, a tube inserted through the urethra and bladder and into the ureter. Stents are used to aid treatment in various ways, such as preventing stone fragments from blocking the flow of urine.

  • superficial: On the surface.

  • tissue: Group of cells in an organism that are similar in form and function.

  • ultrasound: Also referred to as a sonogram. A technique that bounces painless sound waves off organs to create an image of their structure to detect abnormalities.

  • umbilical: Related to or situated in the umbilical cord, the navel or the area of the abdomen that surrounds the navel.

  • umbilical cord: The flexible, often spirally twisted tube that connects the abdomen of the fetus to the mother's placenta through which nutrients are delivered and waste expelled.

  • urachal: Relating to the urachus, which are the remains of the cavity of the allantois that usually disappear during embryo development.

  • urachal sinus: The blind-end opening at the umbilicus that will not drain urine.

  • urachus: The remains of the cavity of the allantois which usually disappears during embryonic development.

  • urea: A waste product found in the blood and caused by the breakdown of protein in the liver. Urea is normally removed from the blood by the kidneys and then excreted in the urine. Urea accumulates in the body of people with renal failure.

  • urge: Strong desire to urinate.

  • urinary: Relating to urine.

  • urinary tract: The system that takes wastes from the blood and carries them out of the body in the form of urine. Passageway from the kidneys to the ureters, bladder and urethra.

  • urinary tract infection: Also referred to as UTI. An illness caused by harmful bacteria, viruses or yeast growing in the urinary tract.

  • urination: The passing of urine.

  • urine: Liquid waste product filtered from the blood by the kidneys, stored in the bladder and expelled from the body through the urethra by the act of urinating (voiding). About 96 percent of which is water and the rest waste products.

  • urologist: A doctor who specializes in diseases of the male and female urinary systems and the male reproductive system. Click here to learn more about urologists. (Download the free Acrobat reader.)

  • urology: Branch of medicine concerned with the urinary tract in males and females and with the genital tract and reproductive system of males.

  • vas: Also referred to as vas deferens. The cordlike structure that carries sperm from the testicle to the urethra.

  • vitelline duct: The duct by which umbilical vesicle remains connected with the alimentary tract of the embryo.

  • void: To urinate, empty the bladder.

  • voiding: Urinating.

  • voiding cystourethrogram: Also referred to as VCUG or voiding cystogram. A specific X-ray that examines the urinary tract. A catheter (hollows tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body)and the bladder is filled with a liquid dye. X-ray images are taken as the bladder fills and empties. The X-rays will show if there is any reverse flow of urine into the ureters and kidneys.

Urachal Abnormalities Anatomical Drawings

click images for a larger view


Urology Care Foundation Impact
See how Urology Care Foundation-supported research has impacted how you manage your urological condition. Learn more.
Urology Care Foundation Impact
    CFC     ICA     Health & Medical Research Charities of America     View our Awards
Urology Care Foundation, Inc.
  • Click here for permission to duplicate or reprint content.
  • © 2015 Urology Care Foundation, Inc. All Rights Reserved.

© 2015 Urology Care Foundation, Inc. All Rights Reserved.