Stress ulcer is suspected when there is upper gastrointestinal bleeding in the appropriate clinical setting, for example, when there is upper gastrointestinal bleeding in elderly patients in a surgical intensive care unit (ICU) with heart and lung disease, or when there is upper gastrointestinal bleeding in patients in a medical ICU who require respirators.

Stress ulcer can be diagnosed after the initial management of gastrointestinal bleeding, the diagnosis can be confirmed by upper GI endoscopy.

The diagnosis is mainly established based on the characteristic symptoms. Stomach pain is usually the first signal of a peptic ulcer. In some cases, doctors may treat ulcers without diagnosing them with specific tests and observe whether the symptoms resolve, thus indicating that their primary diagnosis was accurate.

More specifically, peptic ulcers erode the muscularis mucosae, at minimum reaching to the level of the submucosa (contrast with erosions, which do not involve the muscularis mucosae).

Confirmation of the diagnosis is made with the help of tests such as endoscopies or barium contrast x-rays. The tests are typically ordered if the symptoms do not resolve after a few weeks of treatment, or when they first appear in a person who is over age 45 or who has other symptoms such as weight loss, because stomach cancer can cause similar symptoms. Also, when severe ulcers resist treatment, particularly if a person has several ulcers or the ulcers are in unusual places, a doctor may suspect an underlying condition that causes the stomach to overproduce acid.

An esophagogastroduodenoscopy (EGD), a form of endoscopy, also known as a gastroscopy, is carried out on people in whom a peptic ulcer is suspected. By direct visual identification, the location and severity of an ulcer can be described. Moreover, if no ulcer is present, EGD can often provide an alternative diagnosis.

One of the reasons that blood tests are not reliable for accurate peptic ulcer diagnosis on their own is their inability to differentiate between past exposure to the bacteria and current infection. Additionally, a false negative result is possible with a blood test if the person has recently been taking certain drugs, such as antibiotics or proton-pump inhibitors.

The diagnosis of "Helicobacter pylori" can be made by:

- Urea breath test (noninvasive and does not require EGD);

- Direct culture from an EGD biopsy specimen; this is difficult to do, and can be expensive. Most labs are not set up to perform "H. pylori" cultures;

- Direct detection of urease activity in a biopsy specimen by rapid urease test;

- Measurement of antibody levels in the blood (does not require EGD). It is still somewhat controversial whether a positive antibody without EGD is enough to warrant eradication therapy;

- Stool antigen test;

- Histological examination and staining of an EGD biopsy.

The breath test uses radioactive carbon to detect H. pylori. To perform this exam the person will be asked to drink a tasteless liquid which contains the carbon as part of the substance that the bacteria breaks down. After an hour, the person will be asked to blow into a bag that is sealed. If the person is infected with H. pylori, the breath sample will contain radioactive carbon dioxide. This test provides the advantage of being able to monitor the response to treatment used to kill the bacteria.

The possibility of other causes of ulcers, notably malignancy (gastric cancer) needs to be kept in mind. This is especially true in ulcers of the "greater (large) curvature" of the stomach; most are also a consequence of chronic "H. pylori" infection.

If a peptic ulcer perforates, air will leak from the inside of the gastrointestinal tract (which always contains some air) to the peritoneal cavity (which normally never contains air). This leads to "free gas" within the peritoneal cavity. If the person stands erect, as when having a chest X-ray, the gas will float to a position underneath the diaphragm. Therefore, gas in the peritoneal cavity, shown on an erect chest X-ray or supine lateral abdominal X-ray, is an omen of perforated peptic ulcer disease.

The need for medications to prevent stress ulcer among those in the intensive care unit is unclear. As of 2014, the quality of the evidence is poor. It is unclear which agent is best or if prevention is needed at all. Benefit may only occur in those who are not being fed.

Possible agents include antacids, H2-receptor blockers, sucralfate, and proton pump inhibitors (PPIs). Tentative evidence supports that PPIs may be better than H2 blockers.

Concerns with the use of stress ulcer prophylaxis agents include increased rates of pneumonia and "Clostridium difficile" colitis.

A gastric peptic ulcer is a mucosal perforation which penetrates the muscularis mucosae and lamina propria, usually produced by acid-pepsin aggression. Ulcer margins are perpendicular and present chronic gastritis. During the active phase, the base of the ulcer shows 4 zones: fibrinoid necrosis, inflammatory exudate, granulation tissue and fibrous tissue. The fibrous base of the ulcer may contain vessels with thickened wall or with thrombosis.

In the United Kingdom, the Royal College of Nursing has published guidelines in 'Pressure ulcer risk assessment and prevention' that call for identifying people at risk and taking preventative action; the UK National Standards for Care Homes (UK) to do so as well.

Internationally, the NPUAP, EPUAP and Pan Pacific Pressure Injury Alliance (Australia, New Zealand, Singapore and Hong Kong) published comprehensive evidence-based clinical practice guidelines in 2014. The guideline was developed by an international team of over 100 clinical specialists and updates the 2009 EPUAP and NPUAP clinical guidelines. The guideline includes recommendations on strategies to prevent pressure ulcers including the use of pressure redistributing support surfaces, repositioning and maintaining appropriate nutritional support.

In addition, adequate intake of protein and calories is important. vitamin C has been shown to reduce the risk of pressure ulcers. People with higher intakes of vitamin C have a lower frequency of bed sores in those who are bedridden than those with lower intakes. Maintaining proper nutrition in newborns is also important in preventing pressure ulcers. If unable to maintain proper nutrition through protein and calorie intake, it is advised to use supplements to support the proper nutrition levels. Skin care is also important because damaged skin does not tolerate pressure. However, skin that is damaged by exposure to urine or stool is not considered a pressure ulcer. These skin wounds should be classified as Incontinence Associated Dermatitis.

Some of the investigations done for ulcer are:

- Study of discharging fluid: Culture and sensitivity

- Edge biopsy: Edge contains multiplying cells

- Radiograph of affected area to look for periostitis or osteomyelitis

- FNAC of lymph node

- Chest X-ray and Mantoux test in suspected tuberculous ulcer

Other radiological studies frequently used to assess patients with chronic stomach problems include a barium swallow, where a dye is consumed and pictures of the esophagus and stomach are obtained every few minutes. Other tests include a 24-hour pH study, CT scans or MRI.

Diagnosis is done by direct observation under magnified view of slit lamp revealing the ulcer on the cornea. The use of fluorescein stain, which is taken up by exposed corneal stroma and appears green, helps in defining the margins of the corneal ulcer, and can reveal additional details of the surrounding epithelium. Herpes simplex ulcers show a typical dendritic pattern of staining. Rose-Bengal dye is also used for supra-vital staining purposes, but it may be very irritating to the eyes. In descemetoceles, the Descemet's membrane will bulge forward and after staining will appear as a dark circle with a green boundary, because it does not absorb the stain. Doing a corneal scraping and examining under the microscope with stains like Gram's and KOH preparation may reveal the bacteria and fungi respectively. Microbiological culture tests may be necessary to isolate the causative organisms for some cases. Other tests that may be necessary include a Schirmer's test for keratoconjunctivitis sicca and an analysis of facial nerve function for facial nerve paralysis.

Often, a diagnosis can be made based on the patient's description of their symptoms, but other methods which may be used to verify gastritis include:

- Blood tests:

- Blood cell count

- Presence of "H. pylori"

- Liver, kidney, gallbladder, or pancreas functions

- Urinalysis

- Stool sample, to look for blood in the stool

- X-rays

- ECGs

- Endoscopy, to check for stomach lining inflammation and mucous erosion

- Stomach biopsy, to test for gastritis and other conditions

The symptoms due to bleeding are hematemesis and/or melena.

A Dieulafoy's lesion is difficult to diagnose, because of the intermittent pattern of bleeding. Endoscopically it is not easy to recognize and therefore sometimes multiple views have to be performed over a longer period. Today angiography is a good additional diagnostic, but then it can only be seen during a bleeding at that exact time.

The most confirmatory investigation is endoscopy of upper gastrointestinal tract.

Laboratory

- Individuals with gastric outlet obstruction are often hypochloremic, hypokalemic, and alkalotic due to loss of hydrogen chloride and potassium. High urea and creatinine levels may also be observed if the patient is dehydrated.

Abdominal X-ray

- A gastric fluid level may be seen which would support the diagnosis.

Barium meal and follow through

- May show an enlarged stomach and pyloroduodenal stenosis.

Gastroscopy

- May help with cause and can be used therapeutically.

The tests that are considered to evaluate of the passage of blood in the stool are based on the characteristics of bleeding (color, quantity) and whether or not the person passing blood has a low blood pressure with elevated heart rate, as opposed to normal vital signs. The following tests are combined to determine the causes of the source of bleeding.

- Digital rectal exam (DRE) and fecal occult blood test (FOBT)

- Colonoscopy

- Anoscopy

- Esophagogastroduodenoscopy (EGD)

- Capsule endoscopy

- CT Scan

Melena is defined as dark, tarry stools, often black in color due to partial digestion of the RBCs.

Hematochezia is defined as bright red blood seen in the toilet either inside of, or surrounding the stool.

Hematochezia is typically presumed to come from the lower portion of the GI tract, and the initial steps of diagnosis include a DRE with FOBT, which if positive, will lead to a colonoscopy. If the person has a large amount of blood in their stool, an EGD test may be necessary. If no source of active bleeding is found on these examinations, a capsule endoscopy may be performed, in order to more closely examine the small bowel, which cannot be seen with the other types of studies. With melena, a DRE with FOBT is often also performed, however the suspicion for a source from the upper GI tract is higher, leading first to the use of EGD with the other tests being required if no source is identified. The anoscopy is another type of examination, which can be used along with a colonoscopy, which exams the rectum and distal portion of the descending colon.

The differential diagnosis of gastric outlet obstruction may include: early gastric carcinoma hiatal hernia, gastroesophageal reflux, adrenal insufficiency, and inborn errors of metabolism.

Skin ulcers may take a very long time to heal. Treatment is typically to avoid the ulcer getting infected, remove any excess discharge, maintain a moist wound environment, control the edema, and ease pain caused by nerve and tissue damage.

Topical antibiotics are normally used to prevent the ulcer getting infected, and the wound or ulcer is usually kept clear of dead tissue through surgical debridement.

Commonly, as a part of the treatment, patients are advised to change their lifestyle if possible and to change their diet. Improving the circulation is important in treating skin ulcers, and patients are consequently usually recommended to exercise, stop smoking, and lose weight.

In recent years, advances have been made in accelerating healing of chronic wounds and ulcers. Chronic wounds produce fewer growth hormones than necessary for healing tissue, and healing may be accelerated by replacing or stimulating growth factors while controlling the formation of other substances that work against them.

Leg ulcers can be prevented by using compression stockings to prevent blood pooling and back flow. It is likely that a person who has had a skin ulcer will have it again; use of compression stockings every day for at least 5 years after the skin ulcer has healed may help to prevent recurrence.

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.

Anemia is a common complication of blood in the stool, especially when there is a large amount of blood or bleeding occurs over a long period of time. Anemia is also commonly associated with an iron deficiency, due to the importance of iron in the formation of red blood cells (RBCs). When anemia is diagnosed as a result of blood in the stool, vitamins that are important for RBC formation (folate, vitamin B12, and vitamin C) are frequently prescribed in order to ensure that all the materials are available for those cells that are made.

On x-rays, gas may be visible in the abdominal cavity. Gas is easily visualized on x-ray while the patient is in an upright position. The perforation can often be visualised using computed tomography. White blood cells are often elevated.

A perforated ulcer, is a condition in which untreated ulcer can burn through the wall of the stomach (or other areas of the gastrointestinal tract), allowing digestive juices and food to leak into the abdominal cavity. Treatment generally requires immediate surgery. The ulcer is known initially as a peptic ulcer before the ulcer burns through the full thickness of the stomach or duodenal wall. A diagnosis is made by taking an erect abdominal/chest X-ray (seeking air under the diaphragm). This is in fact one of the very few occasions in modern times where surgery is undertaken to treat an ulcer. Many perforated ulcers have been attributed to the bacterium "Helicobacter pylori". The incidence of perforated ulcer is steadily declining, though there are still incidents where it occurs. Causes include smoking and nonsteroidal anti-inflammatory drugs (NSAIDs). A perforated ulcer can be grouped into a stercoral perforation which involves a number of different things that causes perforation of the intestine wall. The first symptom of a perforated peptic ulcer is usually sudden, severe, sharp pain in the abdomen. The experience is typically so intense that most people precisely recall the exact moment the pain began. The pain is typically at its maximum immediately and persists. It is characteristically made worse by any movement, and greatly intensifies with coughing or sneezing.

Stable patients presenting to A&E (accident and emergency department) or ER (emergency room) with severe abdominal pain will almost always have an abdominal x-ray and/or a CT scan. These tests can provide a differential diagnosis between simple and complex pathologies. However, in the unstable patient, fluid resuscitation and a FAST-ultrasound are done first, and if the latter is positive for free fluid, straight to surgery. They may also provide evidence to the doctor whether surgical intervention is necessary.

Patients will also most likely receive a complete blood count (or full blood count in the U.K.), looking for characteristic findings such as neutrophilia in appendicitis.

Traditionally, the use of opiates or other painkillers in patients with an acute abdomen has been discouraged before the clinical examination, because these would alter the examination. However, the scientific literature does not reveal any negative results from these alterations.

People under 55 years without alarm symptoms can be treated without investigation. People over 55 years with recent onset dyspepsia or those with alarm symptoms should be urgently investigated by upper gastrointestinal endoscopy. This will rule out peptic ulcer disease, medication-related ulceration, malignancy and other rarer causes.

People under the age of 55 years with no alarm features do not need endoscopy but are considered for investigation for peptic ulcer disease caused by "Helicobacter pylori" infection. Investigation for "H. pylori" infection is usually performed when there is a moderate to high prevalence of this infection in the local community or the person with dyspepsia has other risk factors for "H. pylori" infection, related for example to ethnicity or immigration from a high-prevalence area. If infection is confirmed, it can usually be eradicated by medication.

Medication-related dyspepsia is usually related to NSAIDs and can be complicated by bleeding or ulceration with perforation of stomach wall.

Most people with appendicitis recover easily after surgical treatment, but complications can occur if treatment is delayed or if peritonitis occurs. Recovery time depends on age, condition, complications, and other circumstances, including the amount of alcohol consumption, but usually is between 10 and 28 days. For young children (around 10 years old), the recovery takes three weeks.

The possibility of peritonitis is the reason why acute appendicitis warrants speedy evaluation and treatment. People with suspected appendicitis may have to undergo a medical evacuation. Appendectomies have occasionally been performed in emergency conditions (i.e., not in a proper hospital), when a timely medical evacuation was impossible.

Typical acute appendicitis responds quickly to appendectomy and occasionally will resolve spontaneously. If appendicitis resolves spontaneously, it remains controversial whether an elective interval appendectomy should be performed to prevent a recurrent episode of appendicitis. Atypical appendicitis (associated with suppurative appendicitis) is more difficult to diagnose and is more apt to be complicated even when operated early. In either condition, prompt diagnosis and appendectomy yield the best results with full recovery in two to four weeks usually. Mortality and severe complications are unusual but do occur, especially if peritonitis persists and is untreated.

Another entity known as appendicular lump is talked about. It happens when the appendix is not removed early during infection and omentum and intestine adhere to it, forming a palpable lump. During this period, surgery is risky unless there is pus formation evident by fever and toxicity or by USG. Medical management treats the condition.

An unusual complication of an appendectomy is "stump appendicitis": inflammation occurs in the remnant appendiceal stump left after a prior incomplete appendectomy. Stump appendicitis can occur months to years after initial appendectomy and can be identified with imaging modalities like ultrasound.

The mortality rate for Dieulafoy's was much higher before the era of endoscopy, where open surgery was the only treatment option.

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.

MRI use has become increasingly common for diagnosis of appendicitis in children and pregnant patients due to the radiation dosage that, while of nearly negligible risk in healthy adults, can be harmful to children or the developing fetus. In pregnancy, it has been found to be more useful during the second and third trimester, particularly as the enlargening uterus displaces the appendix, making it difficult to find by ultrasound. The periappendiceal stranding that is reflected on CT by fat stranding on MRI appears as increased fluid signal on T2 weighted sequences. First trimester pregnancies are usually not candidates for MRI, as the fetus is still undergoing organogenesis, and there are no long-term studies to date regarding its potential risks or side effects.