Diet and lifestyle are believed to play a large role in whether colorectal polyps form. Studies show there to be a protective link between consumption of cooked green vegetables, brown rice, legumes, and dried fruit and decreased incidence of colorectal polyps.

Most polyps are benign and do not need to be removed. Polyps larger than 1 cm with co-occurring gallstones occurring in people over the age of 50 may have the gallbladder removed (cholecystectomy), especially if the polyps are several or appear malignant. Laparoscopic surgery is an option for small or solitary polyps.

Polypoid lesions of the gallbladder affect approximately 5% of the adult population. The causes are uncertain, but there is a definite correlation with increasing age and the presence of gallstones (cholelithiasis). Most affected individuals do not have symptoms. The gallbladder polyps are detected during abdominal ultrasonography performed for other reasons.

The incidence of gallbladder polyps is higher among men than women. The overall prevalence among men of Chinese ancestry is 9.5%, higher than other ethnic types.

Polyps can be removed during a colonoscopy or sigmoidoscopy using a wire loop that cuts the stalk of the polyp and cauterises it to prevent bleeding. Many "defiant" polyps—large, flat, and otherwise laterally spreading adenomas—may be removed endoscopically by a technique called endoscopic mucosal resection (EMR), which involves injection of fluid underneath the lesion to lift it and thus facilitate surgical excision. These techniques may be employed as an alternative to the more invasive colectomy.

People with juvenile polyps may require yearly upper and lower endoscopies with polyp excision and cytology. Their siblings may also need to be screened regularly. Malignant transformation of polyps requires surgical colectomy.

Screening for colonic polyps as well as preventing them has become an important part of the management of the condition. Medical societies have established guidelines for colorectal screening in order to prevent adenomatous polyps and to minimize the chances of developing colon cancer. It is believed that some changes in the diet might be helpful in preventing polyps from occurring but there is no other way to prevent the polyps from developing into cancerous growths than by detecting and removing them.

According to the guidelines established by the American Cancer Society, individuals who reach the age of 50 should perform an occult blood test yearly. Colon polyps as they grow can sometimes cause bleeding within the intestine, which can be detected with the help of this test. Also, persons in their 50s are recommended to have flexible sigmoidoscopies performed once in 3 to 5 years to detect any abnormal growth which could be an adenomatous polyp. If adenomatous polyps are detected during this procedure, it is most likely that the patient will have to undergo a colonoscopy. Medical societies recommend colonoscopies every ten years starting at age 50 as a necessary screening practice for colon cancer. The screening provides an accurate image of the intestine and also allows the removal of the polyp, if found. Once an adenomatous polyp is identified during colonoscopy, there are several methods of removal including using a snare or a heating device. Colonoscopies are preferred over sigmoidoscopies because they allow the examination of the entire colon; a very important aspect, considering that more than half of the colonic polyps occur in the upper colon, which is not reached during sigmoidoscopies.

It has been statistically demonstrated that screening programs are effective in reducing the number of deaths caused by colon cancer due to adenomatous polyps. While there are risks of complications associated with colonoscopies, those risks are extremely low at approximately 0.35 percent. For comparison, the lifetime risk of developing colon cancer is around 6 percent. As there is a small likelihood of recurrence, surveillance after polyp removal is recommended.

Complete removal of a SSA is considered curative.

Several SSAs confer a higher risk of subsequently finding colorectal cancer and warrant more frequent surveillance. The surveillance guidelines are the same as for other colonic adenomas. The surveillance interval is dependent on (1) the number of adenomas, (2) the size of the adenomas, and (3) the presence of high-grade microscopic features.

Polyps on the vocal folds can take on many different forms, and can sometimes result from vocal abuse, although this is not always the cause. They can occur on one or both vocal folds, and appear as swelling, a bump (similar to a nodule), a stalk-like growth, or a blister-like lesion. Most polyps are larger than nodules, which are more similar to callouses on the vocal folds.

Polyps and nodules can exhibit similar symptoms including hoarseness or breathiness, “rough” or “scratchy” voice, harshness in vocal quality, shooting pain from ear to ear, sensation of having “a lump in the back of the throat”, neck pain, decreased pitch range in the voice, and vocal and bodily fatigue.

If an individual experiences symptoms for more than 2 to 3 weeks, they should see a physician. For a diagnosis, a thorough evaluation of the voice should include a physical examination, preferably by an otolaryngologist (ear, nose, and throat doctor) who specializes in voice, a voice evaluation with a speech-language pathologist (SLP), a neurological examination (in certain cases)

The qualities of the voice that will be evaluated include quality, pitch, loudness, and ability to sustain voicing. In some cases, an instrumental examination may be performed with an endoscope into the mouth or nose; this gives a clear look at the vocal folds and larynx in general. In addition to this, a stroboscope (flashing light) may be used to observe the movement of the vocal folds during speech.

Polyps may be treated with medical, surgical, or behavioral intervention. Surgical intervention involves removing the polyp from the vocal fold. This approach is only used when the growth(s) are very large, or have existed for an extended amount of time. In children, surgical intervention is rare. Existing medical problems may be treated in an effort to reduce the strain and negative impact on the vocal cords. This could include treatment for gastrointestinal reflux disease, allergies, and thyroid problems. Intervention to stop smoking and reduce stress may also be needed. Most people receive behavioral intervention, or vocal therapy, from an SLP. This might involve teaching good vocal hygiene, and reducing or stopping vocal abuse behaviors. Direct voice treatments may be used to alter pitch, loudness, or breathe support to promote good voicing.

Resection is sometimes a part of a treatment plan, but duodenal cancer is difficult to remove surgically because of the area that it resides in—there are many blood vessels supplying the lower body. Chemotherapy is sometimes used to try to shrink the cancerous mass. Other times intestinal bypass surgery is tried to reroute the stomach to intestine connection around the blockage.

A 'Whipple' procedure is a type of surgery that is sometimes possible with this cancer. In this procedure, the duodenum, a portion of the Pancreas (the head), and the gall bladder are usually removed, the small intestine is brought up to the Pylorus (the valve at the bottom of the stomach) and the Liver and Pancreas digestive enzymes and bile are connected to the small intestine below the Pylorus.

The removal of part of the Pancreas often requires taking Pancreatic Enzyme supplements to aid digestion. These are available in the form of capsules by prescription.

It is not unusual for a patient having received a Whipple procedure to feel perfectly well, and to lead his/her normal life without difficulty.

It is important for the procedure to be performed by a surgeon with extensive experience having done and observed the procedure, as specific competence makes a big difference.

Some patients need to be fitted with tubes to either add nutrients (feeding tubes) or drainage tubes to remove excess processed food that can not pass the blockage.

The first line of treatment for nasal polyps is topical steroids. Steroids decrease the inflammation of the sinus mucosa to decrease the size of the polyps and improve symptoms. Topical preparations are preferred in the form of a nasal spray, but are often ineffective for people with many polyps. Steroids by mouth often provide drastic symptom relief, but should not be taken for long periods of time due to their side effects. Because steroids only shrink the size and swelling of the polyp, people often have recurrence of symptoms once the steroids are stopped. Decongestants do not shrink the polyps, but can decrease swelling and provide some relief. Antibiotics are only recommended if the person has a co-occurring bacterial infection.

In people with nasal polyps caused by aspirin or NSAIDs, avoidance of these medications will help with symptoms. Aspirin desensitization has also been shown to be beneficial.

Endoscopic sinus surgery with removal of polyps is often very effective for most people providing rapid symptom relief. Endoscopic sinus surgery is minimally-invasive and is done entirely through the nostril with the help of a camera. Surgery should be considered for those with complete nasal obstruction, uncontrolled runny nose, nasal deformity caused by polyps or continued symptoms despite medical management. Surgery serves to remove the polyps as well as the surrounding inflamed mucosa, open obstructed nasal passages, and clear the sinuses. This not only removes the obstruction caused by the polyps themselves, but allows medications such as saline irrigations and topical steroids to become more effective.

Surgery lasts approximately 45 minutes to 1 hour and can be done under general or local anesthesia. Most patients tolerate the surgery without much pain, though this can vary from patient to patient. The patient should expect some discomfort, congestion, and drainage from the nose in the first few days after surgery, but this should be mild. Complications from endoscopic sinus surgery are rare, but can include bleeding and damage to other structures in the area including the eye or brain.

Many physicians recommend a course of oral steroids prior to surgery to reduce mucosal inflammation, decrease bleeding during surgery, and help with visualization of the polyps. Nasal steroid sprays should be used preventatively after surgery to delay or prevent recurrence. People often have recurrence of polyps even following surgery. Therefore, continued follow up with a combination of medical and surgical management is preferred for the treatment of nasal polyps.

Villous adenoma is a type of polyp that grows in the colon and other places in the gastrointestinal tract and sometimes in other parts of the body. These adenomas may become malignant (cancerous). Villous adenomas have been demonstrated to contain malignant portions in about one third of affected persons, and invasive malignancy in another one third of removed specimens. Colonic resection may be required for large lesions. These can also lead to secretory diarrhea with large volume liquid stools with few formed elements. They are commonly described as secreting large amounts of mucus, resulting in hypokalaemia in patients. On endoscopy a "cauliflower' like mass is described due to villi stretching. Being an adenoma, the mass is covered in columnar epithelial cells.

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.

Most juvenile polyps are benign, however, malignancy can occur. The cumulative lifetime risk of colorectal cancer is 39% in patients with juvenile polyposis syndrome.

Cervical polyps can be removed using ring forceps. They can also be removed by tying surgical string around the polyp and cutting it off. The remaining base of the polyp can then be removed using a laser or by cauterisation. If the polyp is infected, an antibiotic may be prescribed.

In gastroenterology, a sessile serrated adenoma (abbreviated SSA), also known as sessile serrated polyp (abbreviated SSP), is a premalignant flat (or sessile) lesion of the colon, predominantly seen in the cecum and ascending colon.

SSAs are thought to lead to colorectal cancer through the (alternate) "serrated pathway". This differs from most colorectal cancer, which arises from mutations starting with inactivation of the APC gene.

Multiple SSAs may be part of the "serrated polyposis syndrome".

Black pigment gallstones can form in Rokitansky–Aschoff sinuses of the gallbladder after the fourth to fifth decades of life in absence of the typical risk factors for bilirubin suprasaturation of bile. Hence, they are associated with gallstones (cholelithiasis). Cases of gall bladder cancer have also been reported to arise from Rokitansky–Aschoff sinuses.

99% of cervical polyps will remain benign and 1% will at some point show neoplastic change. Cervical polyps are unlikely to regrow.

Polyps can be surgically removed using curettage with or without hysteroscopy. When curettage is performed without hysteroscopy, polyps may be missed. To reduce this risk, the uterus can be first explored using grasping forceps at the beginning of the curettage procedure. Hysteroscopy involves visualising the endometrium (inner lining of the uterus) and polyp with a camera inserted through the cervix. If it is a large polyp, it can be cut into sections before each section is removed. If cancerous cells are discovered, a hysterectomy (surgical removal of the uterus) may be performed. A hysterectomy would usually not be considered if cancer has been ruled out. Whichever method is used, polyps are usually treated under general anesthetic.

It is unclear if removing polyps affects fertility as it has not been studied.

The cancer commonly spreads to the liver, bile duct, stomach, and duodenum.

The most common and most effective treatment is surgical removal of the gallbladder (cholecystectomy) with part of liver and lymph node dissection. However, with gallbladder cancer's extremely poor prognosis, most patients will die within a year of surgery. If surgery is not possible, endoscopic stenting of the biliary tree can reduce jaundice and a stent in stomach may relieve vomiting. Chemotherapy and radiation may also be used with surgery. If gall bladder cancer is diagnosed after cholecystectomy for stone disease (incidental cancer), reoperation to remove part of liver and lymph nodes is required in most cases. When it is done as early as possible, patients have the best chance of long-term survival and even cure.

Inflammatory fibroid polyp, abbreviated IFP, is a benign abnormal growth of tissue projecting into the lumen of the gastrointestinal tract.

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.

Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The symptoms relate to the organ affected and can include obstruction (leading to difficulty swallowing or defecating), abnormal bleeding or other associated problems. The diagnosis often requires endoscopy, followed by biopsy of suspicious tissue. The treatment depends on the location of the tumor, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere. These factors also determine the prognosis.

Overall, the GI tract and the accessory organs of digestion (pancreas, liver, gall bladder) are responsible for more cancers and more deaths from cancer than any other system in the body. There is significant geographic variation in the rates of different gastrointestinal cancers.

Endometrial polyps are usually benign although some may be precancerous or cancerous. About 0.5% of endometrial polyps contain adenocarcinoma cells. Polyps can increase the risk of miscarriage in women undergoing IVF treatment. If they develop near the fallopian tubes, they may lead to difficulty in becoming pregnant. Although treatments such as hysteroscopy usually cure the polyp concerned, recurrence of endometrial polyps is frequent. Untreated, small polyps may regress on their own.