Gastrointestinal Pain: Causes

GI Pathology: Abdominal Pain

Overview:

Gallstone disease, which arises in the gallbladder and biliary system.
Appendicitis, which is inflammation of the vermiform appendix.
Esophagitis, which is inflammation of the esophagus.
Gastritis/ulcer disease of the stomach.
Pancreatitis, which is inflammation of the pancreas.
Several intestinal disorders: inflammatory bowel disease, diverticulitis, ischemia, obstruction, and functional bowel disease.

Pathologies arising in the renal and gynecological systems can also cause abdominal pain.
For infectious illnesses regarding the GI tract, please see: Gastroenteritis, E. coli gastroenteritis

Details

We'll start with those that arise in the gastrointestinal tract.

Esophagitis can cause upper abdominal pain; inflammation of the esophagus is most often caused by acid reflux, medications, and eosinophilic esophagitis. Treatments include proton pump inhibitors to reduce acid production by the stomach.
Gastritis and stomach ulcers are caused by H. pylori infection, drugs, stress, and, in the case of gastritis, autoimmune dysfunction.

Inflammation can travel up and down the esophagus to and from the stomach.
Treatments include proton pump inhibitors, antacids, H2 blockers, and prostaglandins.

GI strictures and obstruction are caused by hernias, adhesions, volvulus, tumors, inflammatory narrowing, foreign bodies, and fecal impaction.

In our diagram, we show scar tissue adhesions that formed after abdominal surgery; adhesions bind and restrict the intestinal tract, which obscures movement of materials.

Diverticulitis occurs when there is inflammation (often with bacterial infection) in diverticula.

– We show diverticula, pouch-like outcroppings of the intestinal wall, and infection in one of them.

Intestinal ischemia can be the result of systemic hypotension, atherosclerosis, blood clots, and constricting fibrosis or strictures that inhibit blood flow; ischemia is more common in the intestines than in the stomach or esophagus.

Inflammatory bowel disease comprises the chronic/remitting autoimmune disorders Crohn's disease and ulcerative colitis.

Patients often experience diarrhea in addition to abdominal cramping and other symptoms. In ulcerative colitis, the diarrhea is frequently bloody, as show in our diagram.
Anti-inflammatories and immune suppressors are often prescribed.

Functional bowel disorders (FBDs) are characterized by disordered brain-gut interactions. The most common FBD is Irritable bowel syndrome, and patients experience constipation and diarrhea with abdominal pain.

Etiologies are uncertain, but are thought to include infection and/or psychosocial causes.

Pathologies that arise in the accessory digestive organs and non-digestive organs.

We'll focus on locations of pain to help us in diagnosis.

Pancreatitis is the result of bile duct stones, alcohol abuse, and/or cigarette smoking.

Early/acute pancreatitis is characterized by elevated serum amylase and lipase levels.
Late/chronic pancreatitis can result in loss of endocrine and exocrine functions (i.e., patients have diabetes mellitus, etc.).
Pancreatitis causes epigastric pain that radiates towards the back.

Gallstone disease causes pain in the right upper abdominal quadrant; we can remember this, because the gallstones get stuck in the biliary system, which is towards the right side of the abdomen.
Appendicitis often presents early on with pain in the peri-navel area that later moves to the right lower abdominal quadrant (where we find the appendix).
Kidney stones cause "flank" pain – pain in the side of the torso; pain can travel to the groin area, too.
Gynecological causes include: ruptured ovarian cysts, pelvic inflammatory disease, ectopic pregnancy, and endometriosis – essentially, anything that causes inflammation and swelling of the uterus or ovaries can cause lower abdominal and back pain.