In most people with peptic ulcer disease, the oedema will usually settle with conservative management with nasogastric suction, replacement of fluids and electrolytes and proton pump inhibitors.

Treatment of gastric outlet obstruction depends on the cause, but is usually either surgical or medical.

Traditionally, nothing by mouth was considered to be mandatory in all cases, but gentle feeding by enteral feeding tube may help to restore motility by triggering the gut's normal feedback signals, so this is the recommended management initially. When the patient has severe, persistent signs that motility is completely disrupted, nasogastric suction and parenteral nutrition may be required until passage is restored. In such cases, continuing aggressive enteral feeding causes a risk of perforating the gut.

Several options are available in the case of paralytic ileus. Most treatment is supportive. If caused by medication, the offending agent is discontinued or reduced. Bowel movements may be stimulated by prescribing lactulose, erythromycin or, in severe cases that are thought to have a neurological component (such as Ogilvie's syndrome), neostigmine. There is also evidence from a systematic review of randomized controlled trials that chewing gum, as a form of 'sham feeding', may stimulate gastrointestinal motility in the post-operative period and reduce the duration of postoperative ileus.

If possible the underlying cause is corrected (e.g. replace electrolytes).

Ileus is a cause of colic in horses due to functional obstruction of the intestines. It most commonly seen in horses postoperatively, especially following colic surgery. Horses experiencing ileus are at risk for gastric rupture due to rapid reflux build-up, and require intense medical management with frequent nasogastric intubation. Ileus may increase adhesion formation, because intestinal segments have more prolonged contact and intestinal distention causes serosal injury and ischemia. It is usually treated with aggressive fluid support, prokinetics, and anti-inflammatories.

Recurrence of gastric dilatation-volvulus attacks can be a problem, occurring in up to 80 percent of dogs treated medically only (without surgery). To prevent recurrence, at the same time the bloat is treated surgically, a right-side gastropexy is often performed, which by a variety of methods firmly attaches the stomach wall to the body wall, to prevent it from twisting inside the abdominal cavity in the future. While dogs that have had gastropexies still may develop gas distension of the stomach, there is a significant reduction in recurrence of gastric volvulus. One study showed that out of 136 dogs that had surgery for gastric dilatation-volvulus, 4.3 percent of those that did have gastropexies had a recurrence, while 54.5 percent of those without the additional surgery recurred. Gastropexies are also performed prophylactically in dogs considered to be at high risk of gastric dilatation-volvulus, including dogs with previous episodes of gastric dilatation-volvulus or with gastrointestinal disease predisposing to gastric dilatation-volvulus, and dogs with a first-order relative (parent or sibling) with a history of gastric dilatation-volvulus.

Precautions that are likely to help prevent gastric dilatation-volvulus include feeding small meals throughout the day instead of one big meal and not exercising immediately before or after a meal.

Endotoxemia is a serious complication of colic and warrants aggressive treatment. Endotoxin (lipopolysaccharide) is released from the cell wall of gram-negative bacteria when they die. Normally, endotoxin is prevented from entering systemic circulation by the barrier function of the intestinal mucosa, antibodies and enzymes which bind and neutralize it and, for the small amount that manages to enter the blood stream, removal by Kupffer cells in the liver. Endotoxemia occurs when there is an overgrowth and secondary die-off of gram negative bacteria, releasing mass quantities of endotoxin. This is especially common when the mucosal barrier is damaged, as with ischemia of the GI tract secondary to a strangulating lesion or displacement. Endotoxemia produces systemic effects such as cardiovascular shock, insulin resistance, and coagulation abnormalities.

Fluid support is essential to maintain blood pressure, often with the help of colloids or hypertonic saline. NSAIDs are commonly given to reduce systemic inflammation. However, they decrease the levels of certain prostaglandins that normally promote healing of the intestinal mucosa, which subsequently increases the amount of endotoxin absorbed. To counteract this, NSAIDs are sometimes administered with a lidocaine drip, which appears to reduce this particular negative effect. Flunixin may be used for this purpose at a dose lower than that used for analgesia, so can be safely given to a colicky horse without risking masking signs that the horse requires surgery. Other drugs that bind endotoxin, such as polymyxin B and Bio-Sponge, are also often used. Polymixin B prevents endotoxin from binding to inflammatory cells, but is potentially nephrotoxic, so should be used with caution in horses with azotemia, especially neonatal foals. Plasma may also be given with the intent of neutralizing endotoxin.

Laminitis is a major concern in horses suffering from endotoxemia. Ideally, prophylactic treatment should be provided to endotoxic horses, which includes the use of NSAIDs, DMSO, icing of the feet, and frog support. Horses are also sometimes administered heparin, which is thought to reduce the risk of laminitis by decreasing blood coagulability and thus blood clot formation in the capillaries of the foot.

Horses are withheld feed when colic signs are referable to gastrointestinal disease. In long-standing cases, parenteral nutrition may be instituted. Once clinical signs improve, the horse will slowly be re-fed (introduced back to its normal diet), while being carefully monitored for pain.

Immediate treatment is the most important factor in a favorable prognosis. A delay in treatment greater than six hours or the presence of peritonitis, sepsis, hypotension, or disseminated intravascular coagulation are negative prognostic indicators.

Historically, GDV has held a guarded prognosis. Although "early studies showed mortality rates between 33% and 68% for dogs with GDV," studies from 2007 to 2012 "reported mortality rates between 10% and 26.8%". Mortality rates approach 10% to 40% even with treatment. A study determined that with prompt treatment and good preoperative stabilization of the patient, mortality is significantly lessened to 10% overall (in a referral setting). Negative prognostic indicators following surgical intervention include postoperative cardiac arrhythmia, splenectomy, or splenectomy with partial gastric resection. Interestingly, a longer time from presentation to surgery was associated with a lower mortality, presumably because these dogs had received more complete preoperative fluid resuscitation and were thus better cardiovascularly stabilized prior to the procedure.

Intestinal decompression by tube placement in a small stoma can also be used to reduce distension and pressure within the gut. The stoma may be a gastrostomy, jejunostomy, ileostomy or cecostomy, and may also be used to feed, in the case of gastrostomy and jejunostomy, or flush the intestines.

Colostomy or ileostomy can bypass affected parts if they are distal to (come after) the stoma. For instance, if only the large colon is affected, an ileostomy may be helpful. Either of these ostomies are typically placed at or a few centimeters below the patients belly button per doctor recommendation based on the affected area of the intestines as well as concerns for patient comfort and future physical growth for children.

The total removal of the colon, called a colectomy or resection of affected parts of the colon may be needed if part of the gut dies (for instance toxic megacolon), or if there is a localised area of dysmotility.

Gastric and colonic pacemakers have been tried. These are strips placed along the colon or stomach which create an electric discharge intended to cause the muscle to contract in a controlled manner.

A potential solution, albeit radical, is a multi-organ transplant. The operation involved transplanting the pancreas, stomach, duodenum, small intestine, and liver, and was performed by Doctor Kareem Abu-Elmagd on Gretchen Miller, the subject of the Discovery Channel program "Surgery Saved My Life".

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.

With early intervention, morbidity and mortality of cases of intestinal obstruction is low. The outcome is in part dependent upon congenital comorbidities and delays in diagnosis and management.

Surgical intervention is nearly always required in form of exploratory laparotomy and closure of perforation with peritoneal wash. Occasionally they may be managed laparoscopically.

Conservative treatment including intravenous fluids, antibiotics, nasogastric aspiration and bowel rest is indicated only if the person is nontoxic and clinically stable.

Proximal enteritis usually is managed medically. This includes nasogastric intubation every 1–2 hours to relieve gastric pressure secondary to reflux, which often produces to 2–10 L, as well as aggressive fluid support to maintain hydration and correct electrolyte imbalances. Maintaining hydration in these patients can be very challenging. In some cases, fluid support may actually increase reflux production, due to the decreased intravascular oncotic pressure from low total protein and albumin levels, leading to loss of much of these IV fluids into the intestinal lumen. These horses will often display dependent edema (edema that collects in locations based on gravity). Colloids such as plasma or Hetastarch may be needed to improve intravascular oncotic pressure, although they can be cost prohibitive for many owners. Reflux levels are monitored closely to help evaluate fluid losses, and horses recovering from DPJ show improved hydration with decreased reflux production and improved attitude.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used for pain relief, reduction of inflammation, and for their anti-endotoxin effects, but care must be taken since they may produce gastrointestinal ulceration and damage the kidneys. Due to a suspected link to "Clostridial" infection, anti-microbials are often administered, usually penicillin or metronidazole. Aminoglycosides should be used with extreme caution due to the risk of nephrotoxicosis (damage to the kidney). The mucosa of the intestines is damaged with DPJ, often resulting in absorption of endotoxin and risking laminitis, so therapy to combat and treat endotoxemia is often employed. This includes treatment with drugs that counteract endotoxin such as Polymyxin B and Bio-Sponge, fluid support, and laminitis prevention such as icing of the feet. Prokinetic drugs such as lidocaine, erythromycin, metoclopramide, and bethanechol are often used to treat the ileus associated with the disease.

Horses are withheld food until reflux returns to less than 1–2 L of production every 4 hours, and gut sounds return, often requiring 3–7 days of therapy. Parenteral nutrition is often provided to horses that are withheld feed for greater than 3–4 days. It is suspected to improve healing and shorten the duration of the illness, since horses often become cachexic due to the protein losing enteropathy associated with this disease.

Surgery may need to be performed to rule out colic with similar presenting signs such as obstruction or strangulation, and in cases that are long-standing (> 7 days) to perform a resection and anastomosis of the diseased bowel. However, some horses have recovered with long-term medical support (up to 20 days).

Surgical management is reserved for fixing anatomical causes of bowel obstruction that interfere with normal function once they are amenable to such intervention. These conditions include:

- Strictures

- Fistulae

- Diverticula

Neonatal bowel obstruction (NBO) or neonatal intestinal obstruction is the most common surgical emergency in the neonatal period. It may occur due to a variety of conditions and has an excellent outcome based on timely diagnosis and appropriate intervention.

In the great majority of cases, sufferers experience no life-altering discomfort, and no treatment is required. If there is pain or discomfort, 3 or 4 sips of room temperature water will usually relieve the pain. Symptomatic patients should elevate the head of their beds and avoid lying down directly after meals. If the condition has been brought on by stress, stress reduction techniques may be prescribed, or if overweight, weight loss may be indicated. Antisecretory drugs like proton pump inhibitors and H receptor blockers can be used to reduce acid secretion. Medications that reduce the lower esophageal sphincter (LES) pressure should be avoided.

However, in some unusual instances, as when the hiatal hernia is unusually large, or is of the paraesophageal type, it may cause esophageal stricture or severe discomfort. About 5% of hiatus hernias are paraesophageal. If symptoms from such a hernia are severe for example if chronic acid reflux threatens to severely injure the esophagus or is causing Barrett's esophagus, surgery is sometimes recommended. However surgery has its own risks including death and disability, so that even for large or paraesophageal hernias, watchful waiting may on balance be safer and cause fewer problems than surgery. Complications from surgical procedures to correct a hiatus hernia may include gas bloat syndrome, dysphagia (trouble swallowing), dumping syndrome, excessive scarring, and rarely, achalasia. Surgical procedures sometimes fail over time, requiring a second surgery to make repairs.

One surgical procedure used is called Nissen fundoplication. In fundoplication, the gastric fundus (upper part) of the stomach is wrapped, or plicated, around the inferior part of the esophagus, preventing herniation of the stomach through the hiatus in the diaphragm and the reflux of gastric acid. The procedure is now commonly performed laparoscopically. With proper patient selection, laparoscopic fundoplication recent studies have indicated relatively low complication rates, quick recovery, and relatively good long term results.

The "treat empirically" route also has its difficulties, which have all come under wide debate and study. Recommendations are varied but seem to find some common ground around the notion that treatment should be individualized to the specific circumstances under which a patient has developed BLS since these circumstances affect the complex microbial make up of the affected bowel.

Tetracyclines have been the mainstay of treatment for BLS, but recent studies have concluded Rifaximin to be very effective in the treatment of BLS. One study by Di Stefano et al., however, concluded Metronidazole to be more effective than Rifaximin in the treatment of BLS.

Horses may develop pharyngitis, laryngitis, or esophagitis secondary to indwelling nasogastric tube. Other complications include thrombophlebitis, laminitis (which subsequently reduces survival rate), and weight loss. Horses are also at increased risk of hepatic injury.

Survival rates for DPJ are 25–94%. Horses that survive the incident rarely have reoccurrence.

Gastric volvulus of unknown cause comprises two thirds of cases and is presumably due to abnormal laxity of the gastrosplenic, gastroduodenal, gastrophrenic, and gastrohepatic ligaments. Type 1 gastric volvulus is more common in adults but has been reported in children.

Gastric volvulus or volvulus of stomach is a twisting of all or part of the stomach by more than 180 degrees with obstruction of the flow of material through the stomach, variable loss of blood supply and possible tissue death. The twisting can occur around the long axis of the stomach: this is called organoaxial or around the axis perpendicular to this, called mesenteroaxial. Obstruction is more likely in organoaxial twisting than with mesenteroaxial while the latter is more associated with ischemia. About one third of the cases are associated with a hiatus hernia. Treatment is surgical.

The classic triad (Borchardt's Triad) of gastric volvulus, described by Borchardt in 1904, consists of severe epigastric pain, retching (due to sour taste in mouth) without vomiting, inability to pass a nasogastric tube and reportedly occurs in 70% of cases. Sometimes severe pain at the top of left shoulder, this may be due to internal bleeding irritating the diaphragm upon respiration.

Gastrointestinal perforation, also known as ruptured bowel, is a hole in the wall of part of the gastrointestinal tract. The gastrointestinal tract includes the esophagus, stomach, small intestine, and large intestine. Symptoms include severe abdominal pain and tenderness. When the hole is in the stomach or early part of the small intestine the onset of pain is typically sudden while with a hole in the large intestine onset may be more gradual. The pain is usually constant in nature. Sepsis, with an increased heart rate, increased breathing rate, fever, and confusion may occur.

The cause can include trauma such as from a knife wound, eating a sharp object, or a medical procedure such as colonoscopy, bowel obstruction such as from a volvulus, colon cancer, or diverticulitis, stomach ulcers, ischemic bowel, and a number of infections including "C. difficile". A hole allows intestinal contents to enter the abdominal cavity. The entry of bacteria results in a condition known as peritonitis or in the formation of an abscess. A hole in the stomach can also lead to a chemical peritonitis due to gastric acid. A CT scan is typically the preferred method of diagnosis; however, free air from a perforation can often be seen on plain X-ray.

Perforation anywhere along the gastrointestinal tract typically requires emergency surgery in the form of an exploratory laparotomy. This is usually carried out along with intravenous fluids and antibiotics. A number of different antibiotics may be used such as piperacillin/tazobactam or the combination of ciprofloxacin and metronidazole. Occasionally the hole can be sewn closed while other times a bowel resection is required. Even with maximum treatment the risk of death can be as high as 50%. A hole from a stomach ulcer occurs in about 1 per 10,000 people per year, while one from diverticulitis occurs in about 0.4 per 10,000 people per year.

Incidence of hiatal hernias increases with age; approximately 60% of individuals aged 50 or older have a hiatal hernia. Of these, 9% are symptomatic, depending on the competence of the lower esophageal sphincter (LES). 95% of these are "sliding" hiatus hernias, in which the LES protrudes above the diaphragm along with the stomach, and only 5% are the "rolling" type (paraesophageal), in which the LES remains stationary, but the stomach protrudes above the diaphragm.

Hiatus hernia are most common in North America and Western Europe and rare in rural African communities. Some have proposed that insufficient dietary fiber and the use of a high sitting position for defecation may increase the risk.

Treatment is surgical, potentially with a laparoscopic resection. In patients with bleeding, strangulation of bowel, bowel perforation or bowel obstruction, treatment involves surgical resection of both the Meckel's diverticulum itself along with the adjacent bowel segment, and this procedure is called a "small bowel resection". In patients without any of the aforementioned complications, treatment involves surgical resection of the Meckel's diverticulum only, and this procedure is called a simple diverticulectomy.

With regards to asymptomatic Meckel's diverticulum, some recommend that a search for Meckel's diverticulum should be conducted in every case of appendectomy/laparotomy done for acute abdomen, and if found, Meckel's diverticulectomy or resection should be performed to avoid secondary complications arising from it.

Infantile pyloric stenosis is typically managed with surgery; very few cases are mild enough to be treated medically.

The danger of pyloric stenosis comes from the dehydration and electrolyte disturbance rather than the underlying problem itself. Therefore, the baby must be initially stabilized by correcting the dehydration and the abnormally high blood pH seen in combination with low chloride levels with IV fluids. This can usually be accomplished in about 24–48 hours.

Intravenous and oral atropine may be used to treat pyloric stenosis. It has a success rate of 85-89% compared to nearly 100% for pyloromyotomy, however it requires prolonged hospitalization, skilled nursing and careful follow up during treatment. It might be an alternative to surgery in children who have contraindications for anesthesia or surgery, or in children whose parents do not want surgery.

Meckel's diverticulum occurs in about 2% of the population. Prevalence in males is 3–5 times higher than in females. Only 2% of cases are symptomatic, which usually presents among children at the age of 2.

Most cases of Meckel's diverticulum are diagnosed when complications manifest or incidentally in unrelated conditions such as laparotomy, laparoscopy or contrast study of the small intestine. Classic presentation in adults includes intestinal obstruction and inflammation of the diverticulum (diverticulitis). Painless rectal bleeding most commonly occurs in toddlers.

Inflammation in the ileal diverticulum has symptoms that mimic appendicitis, therefore its diagnosis is of clinical importance. Detailed knowledge of the pathophysiological properties is essential in dealing with the life-threatening complications of Meckel's diverticulum.