Prucalopride, pyridostigmine, metoclopramide, cisapride, and erythromycin may be used, but they have not been shown to have great efficacy. In such cases, treatment is aimed at managing the complications. Linaclotide is a new drug that received approval from Food and Drug Administration in August 2012 and looks promising in the treatment of chronic intestinal pseudo-obstruction, gastroparesis and inertia coli.

Intestinal stasis, which may lead to bacterial overgrowth and subsequently, diarrhea or malabsorption, is treated with antibiotics.

Nutritional deficiencies are treated by encouraging patients to avoid food high in fat and fibre, which are harder to digest and increase abdominal distention and discomfort, and have small, frequent meals (5–6 per day), focusing on liquids and soft food. Reducing intake of poorly absorbed sugar alcohols may be of benefit. Referral to an accredited dietitian is recommended. If dietary changes are unsuccessful in meeting nutritional requirements and stemming weight loss, enteral nutrition is used. Many patients eventually require parenteral nutrition.

Total parenteral nutrition (TPN) is a form of long-term nutritional treatment needed for patients that have severe pseudoobstruction. After a period of no improvement of intestinal function or motility the decision to start TPN will be made, and the surgical procedure to add a long-term, more permanent IV to administer TPN will occur. Types of IV catheters to be placed will be a PICC line or central line which include mediports, Broviac, or Hickman lines depending on how long the physicians believe the patient will require TPN. Patients that are deemed TPN dependent will require constant checkups to monitor the catheter is working properly, check liver enzyme levels and look for signs of blood infections, as catheter blockage, liver damage, and infections of catheters are the main complications associated with long term TPN use and can result in sepsis and/or additional surgeries if not properly monitored. TPN nutritional feeds are given over a period of several hours to all day infusions, and are a mixture of all the vitamins, minerals, and calories similar to what one would get eating orally daily as well as any other specific nutritional needs the patient has at the moment. TPN format is typically changed depending on loss/gain of weight and bloodwork results, and is specially formulated to meet each individual patient's needs.

Use of octreotide has been described.

Cannabis has long been known to limit or prevent nausea and vomiting from a variety of causes. This has led to extensive investigations that have revealed an important role for cannabinoids and their receptors in the regulation of nausea and emesis. With the discovery of the endocannabinoid system, novel ways to regulate both nausea and vomiting have been discovered that involve the production of endogenous cannabinoids acting centrally. The plant cannabis has been used in clinics for centuries, and has been known to be beneficial in a variety of gastrointestinal diseases, such as emesis, diarrhea, inflammatory bowel disease and intestinal pain. Moreover, modulation of the endogenous cannabinoid system in the gastrointestinal tract may provide a useful therapeutic target for gastrointestinal disorders. While some GI disorders may be controlled by diet and pharmaceutical medications, others are poorly moderated by conventional treatments. Symptoms of GI disorders often include cramping, abdominal pain, inflammation of the lining of the large and/or small intestine, chronic diarrhea, rectal bleeding and weight loss. Patients with these disorders frequently report using cannabis therapeutically.

In a 2012 animal study, cannabichromene was shown to normalize gastrointestinal hypermotility without reducing the transit time. The study notes that this result is of potential clinical interest, as the only drugs available for intestinal dysmotility are often associated with constipation.

Secondary chronic intestinal pseudo-obstruction is managed by treating the underlying condition.

There is no cure for primary chronic intestinal pseudo-obstruction. It is important that nutrition and hydration is maintained, and pain relief is given. Drugs that increase the propulsive force of the intestines have been tried, as have different types of surgery.

Intravenous (IV) hydration often includes supplementation of electrolytes as persistent vomiting frequently leads to a deficiency. Likewise, supplementation for lost thiamine (Vitamin B) must be considered to reduce the risk of Wernicke's encephalopathy. A and B vitamins are depleted within two weeks, so extended malnutrition indicates a need for evaluation and supplementation. In addition, electrolyte levels should be monitored and supplemented; of particular concern are sodium and potassium.

After IV rehydration is completed, patients in general progress to frequent small liquid or bland meals. After rehydration, treatment focuses on managing symptoms to allow normal intake of food. However, cycles of hydration and dehydration can occur, making continuing care necessary. Home care is available in the form of a PICC line for hydration and nutrition (called total parenteral nutrition). Home treatment is often less expensive than long-term or repeated hospitalizations.

A number of antiemetics are effective and safe in pregnancy including: pyridoxine/doxylamine, antihistamines (such as diphenhydramine), and phenothiazines (such as promethazine). With respect to effectiveness, it is unknown if one is superior to another for relieving nausea or vomiting. Limited evidence from published clinical trials suggests the use of medications to treat hyperemesis gravidarum.

While pyridoxine/doxylamine, a combination of vitamin B and doxylamine, is effective in nausea and vomiting of pregnancy, some have questioned its effectiveness in HG.

Ondansetron may be beneficial, however, there are some concerns regarding an association with cleft palate, and there is little high-quality data. Metoclopramide is also used and relatively well tolerated. Evidence for the use of corticosteroids is weak; there is some evidence that corticosteroid use in pregnant women may slightly increase the risk of oral facial clefts in the infant and may suppress fetal adrenal activity. However, hydrocortisone and prednisolone are inactivated in the placenta and may be used in the treatment of hyperemesis gravidarum after 12 weeks.

Treatments for esophagitis include medications to block acid production, to manage pain, and to reduce inflammation. Other treatments include antibiotics and intravenous nutrition.

To treat reflux esophagitis, over the counter antacids, medications that reduce acid production (H-2 receptor blockers), and proton pump inhibitors are recommended to help block acid production and to let the esophagus heal. Some prescription medications to treat reflux esophagitis include higher dose H-2 receptor blockers, proton pump inhibitors, and prokinetics, which help with the emptying of the stomach.

To treat eosinophilic esophagitis, avoiding any allergens that may be stimulating the eosinophils is recommended. As for medications, proton pump inhibitors and steroids can be prescribed. Steroids that are used to treat asthma can be swallowed to treat eosinophil esophagitis due to nonfood allergens. The removal of food allergens from the diet is included to help treat eosinophilic esophagitis.

For infectious esophagitis, a medicine is prescribed based on what type of infection is causing the esophagitis. These medicines are prescribed to treat bacterial, fungal, viral, and/or parasitic infections.

An endoscopy can be used to remove ill fragments. Surgery can be done to remove the damaged part of the esophagus. For reflux esophagitis, a fundooplication can be done to help strengthen the lower esophageal sphincter from allowing backflow of the stomach into the esophagus. As for patients that have a narrowing esophagus, a gastroenterologist can perform a procedure to dilate the esophagus.

Some home remedies and lifestyle changes to help with esophagitis include losing weight, stop smoking, lowering stress, avoid sleeping/lying down after eating, raise your head while laying down, taking medicines correctly, avoiding certain medications, and avoiding foods that cause the reflux that might be causing the esophagitis.

If the disease remains untreated, it can cause scarring and discomfort in the esophagus. If the irritation is not allowed to heal, esophagitis can result in esophageal ulcers. Esophagitis can develop into Barrett's esophagus and can increase the risk of esophageal cancer.

The prognosis for a person with esophagitis depends on the underlying causes and conditions. If a patient has a more serious underlying cause such as a digestive system or immune system issue, it may be more difficult to treat. Normally, the prognosis would be good with no serious illnesses. If there are more causes than one, the prognosis could move to fair.

Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, gallbladder, and pancreas.

The small and large intestines may be affected by infectious, autoimmune, and physiological states. Inflammation of the intestines is called enterocolitis, which may lead to diarrhoea.

Acute conditions affecting the bowels include infectious diarrhoea and mesenteric ischaemia. Causes of constipation may include faecal impaction and bowel obstruction, which may in turn be caused by ileus, intussusception, volvulus. Inflammatory bowel disease is a condition of unknown aetiology, classified as either Crohn's disease or ulcerative colitis, that can affect the intestines and other parts of the gastrointestinal tract. Other causes of illness include intestinal pseudoobstruction, and necrotizing enterocolitis.

Diseases of the intestine may cause vomiting, diarrhoea or constipation, and altered stool, such as with blood in stool. Colonoscopy may be used to examine the large intestine, and a person's stool may be sent for culture and microscopy. Infectious disease may be treated with targeted antibiotics, and inflammatory bowel disease with immunosuppression. Surgery may also be used to treat some causes of bowel obstruction.

The normal thickness of the small intestinal wall is 3–5 mm, and 1–5 mm in the large intestine. Focal, irregular and asymmetrical gastrointestinal wall thickening on CT scan suggests a malignancy. Segmental or diffuse gastrointestinal wall thickening is most often due to ischemic, inflammatory or infectious disease.

Olanzapine, as well as several other neuroleptic drugs, have also has been investigated for the control of CINV. A 2007 study demonstrated Olanzapine's successful potential for this use, achieving a complete response in the acute prevention of nausea and vomiting in 100% of patients treated with moderately and highly emetogenic chemotherapy, when used in combination with palonosetron and dexamethasone. Neuroleptic agents are now indicated for rescue treatment and the control of breakthrough nausea and vomiting.

Some studies and patient groups say that the use of cannabinoids derived from cannabis during chemotherapy greatly reduces the associated nausea and vomiting, and enables the patient to eat. Synthesized tetrahydrocannabinol (also one of the main active substances in marijuana) is marketed as Marinol and may be practical for this application. Natural medical cannabis is also used and recommended by some oncologists, though its use is regulated and it is not legal in all jurisdictions. However, Marinol was less effective than megestrol acetate in helping cancer patients regain lost appetites. A phase III study found no difference in effects of an oral cannabis extract or THC on appetite and quality of life (QOL) in patients with cancer-related anorexia-cachexia syndrome (CACS) to placebo.

Dexamethasone, a corticosteroid, is often used alongside other antiemetic drugs, as it has synergistic action with many of them, although its specific antiemetic mechanism of action is not fully understood. Metoclopramide, a dopamine D receptor antagonist with possible other mechanisms, is an older drug that is sometimes used, either on its own or in combination with others. Histamine blockers such as diphenhydramine or meclozine may be used in rescue treatment. Lorazepam and diazepam may sometimes be used to relieve anxiety associated with CINV before administration of chemotherapy, and are also often used in the case of rescue treatment.

There is no known cure for CVS, but there are medications that can be used for treatment, intervention, and prevention. There is a growing body of publications on both individual cases and the experiences of the CVS cohort. Treatment is usually on an individual basis, based on trial and error.

The most common therapeutic strategies for those already in an attack are maintenance of salt balance by appropriate intravenous fluids and, in some cases, sedation. Having vomited for a long period prior to attending a hospital, patients are typically severely dehydrated. For a number of patients, potent anti-emetic drugs such as ondansetron (Zofran) or granisetron (Kytril), and dronabinol (Marinol) may be helpful in either preventing an attack, aborting an attack, or reducing the severity of an attack. Lifestyle changes may be recommended, such as extended rest and reduction of stress. Because the symptoms of CVS are similar (or perhaps identical) to those of the disease well-identified as "abdominal migraine", treatment of CVS with a regimen of anti-migraine drugs, such as topiramate and amitriptyline, is showing promise in preventing recurrent attacks.

Broad-spectrum benzimidazoles (such as albendazole and mebendazole) are the first line treatment of intestinal roundworm and tapeworm infections. Macrocyclic lactones (such as ivermectin) are effective against adult and migrating larval stages of nematodes. Praziquantel is the drug of choice for schistosomiasis, taeniasis, and most types of food-borne trematodiases. Oxamniquine is also widely used in mass deworming programmes. Pyrantel is commonly used for veterinary nematodiasis. Artemisinins and derivatives are proving to be candidates as drugs of choice for trematodiasis.

In 2015, a treatment for reflux esophagitis was introduced. It involves a small invasive surgery to place a ring of magnetic titanium beads near the lower esophageal sphincter. It is called a magnetic sphincter augmentation device or MSAD. It was made to prevent GERD by keeping the stomach acid out of the esophagus. Before the implantation of the device, the patients in this study were taking proton pump inhibitors. The pilot study for this device resulted in a treatment that "preserves gastric anatomy" and results in "less severe side effects than traditional antireflux surgery." The patient's that had these devices implanted were given a questionnaire for their GERD Health Related Quality of Life (GERD-HRQL) before implantation. There scores improved after the five years and more than 80% discontinued their proton pump inhibitors. The normalization of esophageal pH was achieved by 70% of the patients in the study. At the end of the study, there were "no reports of death, device erosions, device migrations, device malfunctions, or late-occurring device complications."

The study of esophagitis has focused on reflux esophagitis over the years. However, recently, the study of different subtypes has emerged. Researchers have started to study other causes besides acid reflux. Eosinophilic esophagitis and infectious esophagitis are subtypes that target the lining of the esophagus via infection or immune-mediated inflammatory diseases. Other causes of esophagitis are being studied such as how Crohn's disease, caustic injury, chemotherapy, and radiotherapy can have an effect on the esophagus. It is important to realize that not all upper gastrointestinal tract symptoms are due to gastric reflux and to look at the patient's clinical history before diagnosing and treating the patient. It is important to note that there can be more than one underlying cause to esophagitis.

In cases of coinfection, combination therapy with ivermectin and diethylcarbamazine is advocated. However coinfection with malaria and HIV, especially among African women, does not respond well to the current combination therapies. It is more pressing for trichuriasis that the recommended drugs fail to provide positive results. A novel drug tribendimidine, which was approved in China by the CCDC for human use in 2004, has been subjected to clinical trials showing that they are highly effective against major human flukes, ascaris (>90% cure rate) and hookworm (>82%); however with low cure rate for whipworm (<37%).

Several treatment methods are available to help prevent CINV. Pharmaceutical treatment is generally separated into two types: prophylactic (preventative) treatment, given before the dose of chemotherapy agents, and rescue treatment, given to treat breakthrough nausea and vomiting.

One strategy to control the disease in areas where it is common is the treatment of entire groups of people regardless of symptoms via mass drug administration. This is often done among school-age children and is known as deworming. While testing and treating children who are infected looks like it is effective, there is insufficient evidence to conclude that routine deworming, in the absence of a positive test, improves nutrition, haemoglobin, school attendance or school performance.

For this purpose, broad-spectrum benzimidazoles such as mebendazole and albendazole are the drugs of choice recommended by WHO. These anthelminthics are administered in a single dose are safe, relatively inexpensive, and effective for several months. Mebendazole can be given with a single dose twice a day for three consecutive days. Albendazole is given at a single dose. WHO recommends annual treatment in areas where between 20 and 50% of people are infected, and a twice a year treatment if it is over 50%; and in low risk situation (i.e. less than 20% prevalence) case-by-case treatment. In addition to these, pyrantel pamoate is also equally effective on ascaris. However, it has been reported that albendazole, mebendazole, and pyrantel pamoate are not entirely effective against "T. trichiura" with single oral doses in population-based control.

Treatment for protein losing enteropathy depends upon the underlying condition, according to Rychik, et al this could mean treatment of hypoproteinemia or of the intestinal mucosa.

In terms of treatment for PLE after the "Fontan operation" treatment must be equal to the level of hypoproteinemia present. Therefore, it is useful to categorize patients based on their serum albumin levels, if less than normal (typically less than 3.5 g/dL) but greater than 2.5 g/dL, this can be seen as a mild form of protein losing enteropathy. Symptomatic management of edema with furosemide (and aldactone) can provide relief for the individual with mild hypoproteinemia.

Hypersalivation is optimally treated by treating or avoiding the underlying cause. Mouthwash and tooth brushing may have drying effects.

In the palliative care setting, anticholinergics and similar drugs that would normally reduce the production of saliva causing a dry mouth could be considered for symptom management: scopolamine, atropine, propantheline, hyoscine, amitriptyline, glycopyrrolate.

A 2008 systematic review investigated the efficacy of pharmacological interventions for patients who have too much salvia due to clozapine treatment:

Praziquantel is the drug of choice for treatment. Treatment is effective in early or light infections. Heavy infections are more difficult to treat. Studies of the effectiveness of various drugs for treatment of children with "F. buski" have shown tetrachloroethylene as capable of reducing faecal egg counts by up to 99%. Other anthelmintics that can be used include thiabendazole, mebendazole, levamisole and pyrantel pamoate. Oxyclozanide, hexachlorophene and nitroxynil are also highly effective.

Oral anti-parasitic drugs such as praziquantel are the treatment of choice. Treatment with praziquantel has been approved by the U.S. Food and Drug Administration and is quite effective against these parasites. Usual treatments are with praziquantel (5–10 mg/kg, single-administration) or niclosamide (adults and children over 6 years: 2 g, single-administration after a light breakfast, followed after 2 hours by a laxative; children aged 2–6 years: 1 g; children under 2 years: 500 mg). Albendazole is also highly effective. Atrabine is quite effective but has adverse effects in humans.

If complications of helminthiasis, such as intestinal obstruction occur, emergency surgery may be required. Patients who require non-emergency surgery, for instance for removal of worms from the biliary tree, can be pre-treated with the anthelmintic drug albendazole.

Infection can be prevented by immersing vegetables in boiling water for a few seconds to kill the infective metacercariae, avoiding the use of untreated feces ("nightsoil") as a fertilizer, and maintenance of proper sanitation and good hygiene. Additionally, snail control should be attempted.

Treatment of acute rotavirus infection is nonspecific and involves management of symptoms and, most importantly, maintenance of hydration. If untreated, children can die from the resulting severe dehydration. Depending on the severity of diarrhea, treatment consists of oral rehydration, during which the child is given extra water to drink that contains small amounts of salt and sugar. Some infections are serious enough to warrant hospitalisation where fluids are given by intravenous drip or nasogastric tube, and the child's electrolytes and blood sugar are monitored. Antibiotics are not recommended.

Rotavirus infections rarely cause other complications and for a well managed child the prognosis is excellent.

Treatment is symptomatic and aims to prevent dehydration in young pigs, using products such as electrolyte and energy supplements. Good biosecurity protocols such as adequate quarantine, isolation of cases, and disinfection help prevent entry or spread of the disease in the herd. In Canada, the Canadian Swine Health Board developed detailed protocols on how to adequately disinfect transportation vehicles for live hogs and ensure the quality of the disinfecttion protocol.

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.

The fundamental prevention strategy is hygiene and sanitation. Secondary measures include stricter meat-inspection standards, livestock confinement, health education, safe meat preparation, mass drug therapy, and identifying and treating human and pig carriers. Moreover, a high level of sanitation and prevention of human faecal contamination of pig feeds also plays a major role in prevention. Infection can be prevented with proper disposal of human faeces around pigs, cooking meat thoroughly and/or freezing the meat at −10 °C for 5 days. For human cysticercosis, dirty hands are attributed to be the primary cause, and especially common among food handlers.

Proper cooking of meat is an effective prevention. For example, cooking (56 °C for 5 minutes) of beef viscera destroys cysticerci. Refrigeration, freezing (−10 °C for 9 days) or long periods of salting is also lethal to cysticerci. Inspection of beef and proper disposal of human excreta are also important measures.

Emesis (induction of vomiting) is the generally recommended treatment if a dog has eaten grapes or raisins within the past two hours. A veterinarian may use an emetic such as apomorphine to cause the dog to vomit. Further treatment may involve the use of activated charcoal to adsorb remaining toxins in the gastrointestinal tract and intravenous fluid therapy in the first 48 hours following ingestion to induce diuresis and help to prevent acute renal failure. Vomiting is treated with antiemetics and the stomach is protected from uremic gastritis (damage to the stomach from increased BUN) with H receptor antagonists. BUN, creatinine, calcium, phosphorus, sodium, and potassium levels are closely monitored. Dialysis of the blood (hemodialysis) and peritoneal dialysis can be used to support the kidneys if anuria develops. Oliguria (decreased urine production) can be treated with dopamine or furosemide to stimulate urine production.

The prognosis is guarded in any dog developing symptoms of toxicosis. A negative prognosis has been associated with oliguria or anuria, weakness, difficulty walking, and severe hypercalcemia (increased blood calcium levels).