A 2002 systemic review of herbal products found that several herbs, including peppermint and caraway, have anti-dyspeptic effects for non-ulcer dyspepsia with "encouraging safety profiles". A 2004 meta-analysis of the multiple herbal extract Iberogast found it to be more effective than placebo in people with functional dyspepsia.

Antacids and sucralfate were found to be no better than placebo in a literature review. H2-RAs have been shown to have marked benefit in poor quality trials (30% relative risk reduction), but only a marginal benefit in good quality trials. Prokinetic agents would empirically seem to work well since delayed gastric emptying is considered a major pathophysiological mechanism in functional dyspepsia. They have been shown in a meta-analysis to produce a relative risk reduction of up to 50%, but the studies evaluated to come to this conclusion used the drug cisapride which has since been removed from the market (now only available as an investigational agent) due to serious adverse events such as torsades, and publication bias has been cited as a potential partial explanation for such a high benefit. Modern prokinetic agents such as metoclopramide, erythromycin and tegaserod have little or no established efficacy and often result in substantial side effects. Simethicone has been found to be of some value, as one trial suggests potential benefit over placebo and another shows equivalence with cisapride. So, with the somewhat recent advent of the proton pump inhibitor (PPI) class of medications, the question of whether these new agents are superior to traditional therapy has arisen.

Currently, PPIs are, depending on the specific drug, FDA indicated for erosive esophagitis, gastroesophageal reflux disease (GERD), Zollinger-Ellison syndrome, eradication of H. pylori, duodenal and gastric ulcers, and NSAID-induced ulcer healing and prevention, but not functional dyspepsia. There are, however, evidence-based guidelines and literature that evaluate the use of PPIs for this indication. A helpful chart summarizing the major trials is available from the functional dyspepsia guidelines published in the World Journal of Gastroenterology in 2006.

Smoking has been linked to a variety of disorders of the stomach. Tobacco is known to stimulate acid production and impairs production of the protective mucus. This leads to development of ulcers in the majority of smokers.

Chronic stomach problems have also been linked to excess intake of alcohol. It has been shown that alcohol intake can cause stomach ulcer, gastritis and even stomach cancer. Thus, avoidance of smoking and excess alcohol consumption can help prevent the majority of chronic stomach disorders.

One of the most causes of chronic stomach problems is use of medications. Use of aspirin and other non-steroidal anti-inflammatory drugs to treat various pain disorders can damage lining of the stomach and cause ulcers. Other medications like narcotics can interfere with stomach emptying and cause bloating, nausea, or vomiting.

The majority of chronic stomach problems are treated medically. However, there is evidence that a change in life style may help. Even though there is no specific food responsible for causing chronic stomach problems, experts recommend eating a healthy diet which consists of fruits and vegetables. Lean meat should be limited. Moreover, people should keep a diary of foods that cause problems and avoid them.

There are many tools for investigating stomach problems. The most common is endoscopy. This procedure is performed as an outpatient and utilizes a small flexible camera. The procedure does require intravenous sedation and takes about 30–45 minutes; the endoscope is inserted via the mouth and can visualize the entire swallowing tube, stomach and duodenum. The procedure also allows the physician to obtain biopsy samples. In many cases of bleeding, the surgeon can use the endoscope to treat the source of bleeding with laser, clips or other injectable drugs.

H2 antagonists or proton-pump inhibitors decrease the amount of acid in the stomach, helping with healing of ulcers.

When "H. pylori" infection is present, the most effective treatments are combinations of 2 antibiotics (e.g. clarithromycin, amoxicillin, tetracycline, metronidazole) and a proton-pump inhibitor (PPI), sometimes together with a bismuth compound. In complicated, treatment-resistant cases, 3 antibiotics (e.g. amoxicillin + clarithromycin + metronidazole) may be used together with a PPI and sometimes with bismuth compound. An effective first-line therapy for uncomplicated cases would be amoxicillin + metronidazole + pantoprazole (a PPI).

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.

Management of symptoms for patients within this subgroup of the GERD spectrum is difficult. Once these patients are identified, behavioural and dietary changes are advised. Dietary modifications may include limiting the intake of chocolate, caffeine, acidic food and liquids, gaseous beverages and foods high in fat. Behavioral changes may include weight loss, cessation of smoking, limiting alcohol consumption and avoiding the ingestion of food shortly before bed. Lifestyle changes in children diagnosed with LPR include dietary modifications to avoid foods that will aggravate reflux (e.g., chocolate or acidic and spicy food), altering positioning (e.g., sleeping on your side), modifying the textures of foods (e.g., thickening feeds to heighten awareness of the passing bolus), and eliminating the intake of food before bed.

Proton pump inhibitors (PPIs) are the leading pharmaceutical intervention chosen for the relief and reduction of LPR and are typically recommended for ongoing use twice a day for a period of 3–6 months. PPIs have been shown to be ineffective in very young children and are of uncertain efficacy in older children, for whom their use has been discouraged. While PPIs may provide limited clinical benefits in some adults, there is insufficient evidence to support routine use. Many studies show that PPIs are not more effective than placebos in treating LPR.

When medical management fails, Nissen fundoplication can be offered. However, patients should be advised that surgery may not result in complete elimination of LPR symptoms and even with immediate success, recurrence of symptoms later on is still possible.

One way to assess treatment outcomes for LPR is through the use of voice quality measures. Both subjective and objective measures of voice quality can be used to assess treatment outcomes. Subjective measures include scales such as the Grade, Roughness, Breathiness, Asthenia, Strain Scale (GRBAS); the Reflux Symptom Index; the Voice Handicap Index (VHI); and a voice symptom scale. Objective measures often rely on acoustic parameters such as jitter, shimmer, signal-to-noise ratio, and fundamental frequency, among others. Aerodynamic measures such as vital capacity and maximum phonation time (MPT) have also been used as an objective measure. However, there is not yet a consensus on how best to use the measures or which measures are best to assess treatment outcomes for LPR.

Even though anatomically part of the GI tract, diseases of the mouth are often not considered alongside other gastrointestinal diseases. By far the most common oral conditions are plaque-induced diseases (e.g. gingivitis, periodontitis, dental caries). Some diseases which involve other parts of the GI tract can manifest in the mouth, alone or in combination, including:

- Gastroesophageal reflux disease can cause acid erosion of the teeth and halitosis.

- Gardner's syndrome can be associated with failure of tooth eruption, supernumerary teeth, and dentigerous cysts.

- Peutz–Jeghers syndrome can cause dark spots on the oral mucosa or on the lips or the skin around the mouth.

- Several GI diseases, especially those associated with malabsorption, can cause recurrent mouth ulcers, atrophic glossitis, and angular cheilitis (e.g. Crohn's disease is sometimes termed orofacial granulomatosis when it involves the mouth alone).

- Sideropenic dysphagia can cause glossitis, angular cheilitis.

Initial management includes the relief of symptoms and correcting electrolyte and fluid imbalance that may occur with vomiting. Antiemetics, such as dimenhydrinate, are used to treat the nausea. Pain may be treated with anti-inflammatories, NSAIDs such as ketorolac or diclofenac. Opioids, such as morphine, less commonly may be used. NSAIDs are more or less equivalent to opioids. Hyoscine butylbromide, an antispasmodic, is also indicated in biliary colic.

In biliary colic, the risk of infection is minimal and therefore antibiotics are not required. Presence of infection indicates cholecystitis.

It is unclear whether those experiencing a gallstone attack should receive surgical treatment or not. The scientific basis to assess whether surgery outperformed other treatment was insufficient and better studies were needed as of a SBU report in 2017. Treatment of biliary colic is dictated by the underlying cause. The presence of gallstones, usually visualized by ultrasound, generally necessitates a surgical treatment (removal of the gall bladder, typically via laparoscopy). Removal of the gallbladder with surgery, known as a cholecystectomy, is the definitive surgical treatment for biliary colic. A 2013 Cochrane review found tentative evidence to suggest that early gallbladder removal may be better than delayed removal. Early laparoscopic cholescystectomy happens within 72 hours of diagnosis. In a Cochrane review that evaluated receiving early versus delayed surgery, they found that 23% of those who waited on average 4 months ended up in hospital for complications, compared to none with early intervention with surgery. Early intervention has other advantages including reduced number of visits to the emergency department, less conversions to an open surgery, less operating time required, reduced time in hospital post operatively. The Swedish agency SBU estimated in 2017 that increasing acute phase surgeries could

free multiple in-hospital days per patient and would additionally spare pain and suffering in wait of receiving an operation. The report found that those with acute inflammation of the gallbladder can be surgically treated in the acute phase, within a few days of symptom debut, without increasing the risk for complications (compared to when the surgery is done later in an asymptomatic stage).

Since 1992, chronic gastritis lesions are classified according to the Sydney system.

Chronic gastritis is a chronic inflammation of the gastric mucosa.

LPR was not discussed as a separate condition from GERD until the 1970s and 1980s. However, at around the same time that GERD was first recognized as a clinical entity in the mid-1930s, a link between gut symptoms and airway disease was suggested. Later, acid-related laryngeal s and granulomas were reported in 1968. Subsequent studies suggested that acid reflux might be a contributory factor in other laryngeal and respiratory conditions. In 1979, the link between these airway symptoms and reflux of gastric contents was first documented. At the same time, treatment of reflux disease results was shown to eliminate these airway symptoms.

Preventive measures for visitors to tropical areas where the condition exists include steps to reduce the likelihood of gastroenteritis. These may comprise using only bottled water for drinking, brushing teeth, and washing food, and avoiding fruits washed with tap water (or consuming only peeled fruits, such as bananas and oranges). Basic sanitation is necessary to reduce fecal-oral contamination and the impact of environmental enteropathy in the developing world.

Pancreatic pseudocyst treatment should be aimed at avoiding any complication (1 in 10 cases become infected). They also tend to rupture, and have shown that larger cysts have a higher likelihood to become more symptomatic, even needing surgery. If no signs of infection are present, initial treatment can include conservative measures such as bowel rest (NPO), parenteral nutrition (TPN), and observation. Serum amylase levels can be trended. If symptoms do not improve by 6 weeks, surgical intervention may be appropriate.

In the event of surgery:

- Cystogastrostomy: In this surgical procedure a connection is created between the back wall of the stomach and the cyst such that the cyst drains into the stomach.

- Cystjejunostomy: In this procedure a connection is created between the cyst and the small intestine so that the cyst fluid directly into the small intestine.

- Cystduodenostomy: In this procedure a connection is created between the duodenum (the first part of the intestine) and the cyst to allow drainage of the cyst content into duodenum. The type of surgical procedure depends on the location of the cyst. For pseudocysts that occur in the head of the pancreas a cystduodenostomy is usually performed.

Constipation is believed to be caused by decreased bowel mobility secondary to elevated progesterone (normal in pregnancy), which can lead to greater absorption of water, but it can also be caused or worsened by iron supplementation. It causes the "smooth muscle" along the walls of the intestines to relax. Thus, making sure that the future mother will absorb as much nutrients from her diet as possible in order to nourish the fetus and herself. As a side effect the feces can get extremely dehydrated and hard to pass. Constipation can decrease as pregnancy progresses, with a rate as high as 39% at 14 weeks of gestation reducing to 20% at 36 weeks in one study at a time when iron supplementation was common.

Dietary modification with more fiber or fiber supplementation. Also, increased PO fluids, stool softeners, bulking agents and eating fruit and fiber enriched foods often help. There is not enough evidence to say how best to treat constipation in pregnancy. Stimulant laxatives may help but also cause diarrhoea and abdominal pain. Fibre supplementation may also help.

A woman experiencing sudden defecation should report this to her practitioner.

Dilation of veins in legs caused by relaxation of smooth muscle and increased intravascular pressure due to fluid volume increase. Treatment involves elevation of the legs and pressure stockings to relieve swelling along with warm sitz baths to decrease pain. There is a small amount of evidence that rutosides (a herbal remedy) may relieve symptoms of varicose veins in late pregnancy but it is not yet known if rutosides are safe to take in pregnancy.

Risk factors include obesity, lengthy standing or sitting, constrictive clothing and constipation and bearing down with bowel movements

Getting rid of "H. pylori" in those who are infected decreases the risk of stomach cancer, at least in those who are Asian. A 2014 meta-analysis of observational studies found that a diet high in fruits, mushrooms, garlic, soybeans, and green onions was associated with a lower risk of stomach cancer in the Korean population. Low doses of vitamins, especially from a healthy diet, decrease the risk of stomach cancer. A previous review of antioxidant supplementation did not find supporting evidence and possibly worse outcomes.

Once diagnosed, tropical sprue can be treated by a course of the antibiotic tetracycline or sulphamethoxazole/trimethoprim (co-trimoxazole) for 3 to 6 months.

Supplementation of vitamins B and folic acid improves appetite and leads to a gain in weight.

The stomach is a muscular organ of the gastrointestinal tract that holds food and begins the digestive process by secreting gastric juice. The most common cancers of the stomach are adenocarcinomas but other histological types have been reported. Signs vary but may include vomiting (especially if blood is present), weight loss, anemia, and lack of appetite. Bowel movements may be dark and tarry in nature. In order to determine whether cancer is present in the stomach, special X-rays and/or abdominal ultrasound may be performed. Gastroscopy, a test using an instrument called endoscope to examine the stomach, is a useful diagnostic tool that can also take samples of the suspected mass for histopathological analysis to confirm or rule out cancer. The most definitive method of cancer diagnosis is through open surgical biopsy. Most stomach tumors are malignant with evidence of spread to lymph nodes or liver, making treatment difficult. Except for lymphoma, surgery is the most frequent treatment option for stomach cancers but it is associated with significant risks.

A pancreatic pseudocyst is a circumscribed collection of fluid rich in pancreatic enzymes, blood, and necrotic tissue, typically located in the lesser sac of the abdomen. Pancreatic pseudocysts are usually complications of pancreatitis, although in children they frequently occur following abdominal trauma. Pancreatic pseudocysts account for approximately 75% of all pancreatic masses.

There are no specific guidelines for the treatment of diabetes and disordered eating, but the standard approach for treatment of two complex conditions as multidisciplinary team of professionals which in this case could include an endocrinologist, psychiatrist, psychologist, dietician, etc.

Other important issues related to the treatment of hookworm are reinfection and drug resistance. It has been shown that reinfection after treatment can be extremely high. Some studies even show that 80% of pretreatment hookworm infection rates can be seen in treated communities within 30–36 months. While reinfection may occur, it is still recommended that regular treatments be conducted as it will minimize the occurrence of chronic outcomes. There are also increasing concerns about the issue of drug resistance. Drug resistance has appeared in front-line anthelmintics used for livestock nematodes. Generally human nematodes are less likely to develop resistance due to longer reproducing times, less frequent treatment, and more targeted treatment. Nonetheless, the global community must be careful to maintain the effectiveness of current anthelmintic as no new anthelmintic drugs are in the late-stage development.

The most common treatment for hookworm are benzimidazoles, specifically albendazole and mebendazole. BZAs kill adult worms by binding to the nematode’s β-tubulin and subsequently inhibiting microtubule polymerization within the parasite. In certain circumstances, levamisole and pyrantel pamoate may be used. A 2008 review found that the efficacy of single-dose treatments for hookworm infections were as follows: 72% for albendazole, 15% for mebendazole, and 31% for pyrantel pamoate. This substantiates prior claims that albendazole is much more effective than mebendazole for hookworm infections. Also of note is that the World Health Organization does recommend anthelmintic treatment in pregnant women after the first trimester. It is also recommended that if the patient also suffers from anemia that ferrous sulfate (200 mg) be administered three times daily at the same time as anthelmintic treatment; this should be continued until hemoglobin values return to normal which could take up to 3 months.

Hookworm infection can be treated with local cryotherapy when the hookworm is still in the skin.

Albendazole is effective both in the intestinal stage and during the stage the parasite is still migrating under the skin.

In case of anemia, iron supplementation can cause relief symptoms of iron deficiency anemia. However, as red blood cell levels are restored, shortage of other essentials such as folic acid or vitamin B12 may develop, so these might also be supplemented.