Gastroesophageal Reflux Disease (GERD)

The initial symptoms consist of chest pain on heartburn due to the mucosa injury that may worsen after the ingestion of food or drugs.

Ethiology

GERD arises from conditions that lead to successive expositions of acids on the esophagus mucosa. These conditions (hormones, nerve agents, food and others) include disturbs that increase the LES spontaneous relaxation frequency. That conditions that increase the stomach volume or pressure (increased production of acid and pyloric obstruction) also contribute to esophagitis. Coffee and tobacco cause relaxation of the cardia.

The hiatal hernia (proximal portion of the stomach that slides to the chest cavity) causes descent LES and consequently the reflux occurrence.

Pathology and Pathogenesis

The LES tonic contraction allows a effective barrier to the acid reflux of stomach. These barrier efficiency can be changed by LES tone loss, increased frequency of the transitory relaxation and increased stomach volume, that may become the reflux acid enough to cause pain and erosion. The recurrent reflux can cause mucosa injury and inflammation (esophagitis resulting from granulocytes and eosinophils infiltration with basal cell hyperplasia and blooding ulcers formation). The reflux predisposes the occurrence of more reflux due to the cicatrisation of the inflamed epithelium.  

On regular conditions, the LES transient relaxations are accompanied by the increased esophageal peristalsis. Thus, the individuals with defects on the excitatory pathways that promote peristalsis may be at increased risk of developing esophagic reflux.

Clinical Manifestations

The usual symptom is heartburn, aggravated by a supine position. It can be developed a stenosis (esophagus narrowing) in the distal portion of the esophagus. The progressive obstruction manifests itself in the form of dysphagia. Other reflux complications include bleeding or perforation and pneumonia due to the gastric aspiration into the lungs.

Smoking and alcohol, associated to recurrent reflux, result in changes on the esophagic epithelium (columnar to squamous), called as Barrett’s Esophagus (it mat lead to adenocarcinoma development)

Treatament

1. Decreased stomach pressure (drugs that promote gastric emptying; avoid eating a lot before going to bed)

2. Decreased gastric acidity (antacids)

3. Maintaining of cardia pressure (reduce alcohol, coffee and fat; eat little portions each time)

4. Protection of the esophagus mucosa.

Diarrhea

Diarrhea is characterized by the elimination of feces that present excessive volume and frequency, and are abnormally liquid – more than 3 stools for day. The subjective evaluation of the feces by the patient is influenced by his bowel habits. The diarrhea can be acute (up to 3 to 4 week with infectious cause) or chronic (more than 4 weeks).

The diarrhea can be classified as osmotic, secretory or oily.

The osmotic diarrhea is caused by the poor nutrients absorption or by the poor absorption of electrolytes that retain the water in the lumen. The secretory diarrhea occurs when the secretory cells maintain a high rate of liquid transportation of the GI tract to the lumen. The oily diarrhea (by poor absorption) occurs when the ability to digest or absorb a certain nutrient is deficient.

Ethiology

The flow in the GI tract involves the massive discharge of liquid in the lumen and its absorption, causing the a dynamic balanced state. Changes in these characteristics (excessive osmotic charge, increased discharge or decreased liquid absorption) can origin diarrhea.

Causes:

Osmotic diarrhea –low absorbable solutes ingest (fructose, magnesium salts, phosphate and citrate anion); poor absorption of carbohydrates (flatulence by the sugar digestion made by bacteria).

 Secretory diarrhea – the substances that stimulate the electrolyte discharge by the bowel mucosa by the increased AMPc or GMPc (enterotoxins or production of VIP by the pancreas tumours).

Inflamatory diarrhea – organic injury of the bowel (colon) where occurs a decrease of water absorption and a production of exudate rich in proteins and sometimes pus (diarrhea with mucus, blood and pus of bacterial cause or non-infectious).  

Motor (mobility) – increased peristalsis by prokinetic agents, decreasing the available time for the absorption of any nutrient or liquid.

Pathology and Pathogenesis

The infectious agents are the most important cause of diarrhea because they cause severe diseases that sometimes are fatal. Diarrhea  caused by infectious agents symptoms are caused by toxins that changes the bowel discharge and the absorption.   

Clinical Manifestations

Depending of its cause, intensity and chronicity, the most common signs consists of dehydration (severe diahrrea mostly in children), height loss and specific vitamin deficiency syndrome (glossitis, stomatitis). It may also be hypokalemia and metabolic acidosis (bicarbonate loss).

Inflammatory Bowel Disease - Crohn’s and Colitis

The non-inflamatory bowel disease is differentiated from the infectious for exclusion because it is characterized by recurrent episodes of diarrhea with mucus and leukocytes.

Ethiology

There are two forms of inflammatory bowel disease: Crohn’s Disease (it is transmural and granulomatous) and Ulcerative Colitis (superficial and confined to the colon mucosa).

Pathology and Pathogenesis

Microorganisms, dietary factors, genetic factors and deficient immune answers contribute for Crohn’s Disease that is characterized by and uncontrolled inflammation. The ulcerative colitis can be originated by infections, allergies and dietary components, immune answers to bacteria and psychosocial factors.

The common characteristic of inflammatory bowel diseases consists in the mucosal ulceration and the GI tract inflammation.

Clinical Manifestations

A.    Crohn’s Disease

It can occur in any area of the GI tract in a discontinuous manner. It is characterized by ulceration and inflammation affecting the entire intestinal wall thickness. The disease complications consists are perforation, fistula formation, abscesses formation and small bowel obstruction.

The patients have symptoms outside the GI tract: skin, eyes and mucosa inflammatory disorders,  renal disorders (oxlate absorption associated to steatorrhea); thromboembolic and amyloidosis disease (disease in which amyloidosis, a rare protein that usually doesn’t exist in our body,  accumulates in several tissues). The patients may also present chronic diarrhea with periods of remission, height loss, anorexia, rectal bleeding and malabsorption of iron and B12 vitamin.

B.    Ulcerative Colitis

It is restricted to the colon and rectum mucosa. The obstruction, perforation and fistula formation aren’t complications because the colitis affects only the mucosa. There is a higher risk of developing carcinoma. It is characterized for acute and severe crises, and is more often in younger adults

It is manifested by feces with mucus and blood (severe anemia), diarrhea and peritonitis fistula.

Diverticular Disease

Constipation and lower abdominal pain with intermittent and unpredictable crampy. The patient with diverticulitis presents fever and peritoneal irritation (absent bower sons). The patient with diverticular bleeding presents bloody feces.

Ethiology

The diverticular disease results from a deformation acquired in the colon (sigmoid colon), when occurs the lining dilatation. It is more common in people older than 40 and in industrialized countries. Its prevalence it’s increased by a low-fiber diet with consequent increased constipation.

Pathology and Pathogenisis

A.    Diverticulosis

Individuals with genetic disease involving the connective tissue, as Ehlers-Danlos and Marfan Syndrome, are characterized by the disease appearance on a younger age. The decrease of fibers become harder the feces propulsion, causing vigorous muscular contraction of the colon wall, that can lead to abdominal pain that is the major symptom of the disease. The pain can last several hours or days, and during that period of time it may also occur constipation, diarrhea and flatulence.

B.    Diverticular bleeding

It is painless and arises because the colon intramural arteries are associated to the diverticular sac, leading to the occurrence of rupture and bleeding.

C.    Diverticulitis

It occurs when exists a inflamation on the diverticulum wall, in response to the irritation caused by fecal material. The patient presents abdominal pain, fever, intestinal necrosis and fistula formation.