Abdominal pain

Differential diagnosis

The most frequent reason for abdominal pain are gastroenteritis (13%), irritable bowel syndrome (8%), urinary tract problems (5%), inflammation of the stomach (5%) and constipation (5%). In about 30% of cases, the cause is not determined. About 10% of cases have a more serious cause including gallbladder (stones or biliary dyskinesia) or pancreas problems (4%), diverticulitis (3%), appendicitis (2%) and cancer (1%). More common in those who are older, mesenteric ischemia and abdominal aortic aneurysms are other serious causes.

A more extensive list includes the following:

Gastrointestinal

GI tract

Inflammatory: gastroenteritis, appendicitis, gastritis, esophagitis, diverticulitis, Crohn's disease, ulcerative colitis, microscopic colitis

Obstruction: hernia, intussusception, volvulus, post-surgical adhesions, tumours, severe constipation, hemorrhoids

Vascular: embolism, thrombosis, hemorrhage, sickle cell disease, abdominal angina, blood vessel compression (such as celiac artery compression syndrome), superior mesenteric artery syndrome, postural orthostatic tachycardia syndrome

Digestive: peptic ulcer, lactose intolerance, coeliac disease, food allergies

Glands

Bile system

Inflammatory: cholecystitis, cholangitis

Obstruction: cholelithiasis, tumours

Liver

Inflammatory: hepatitis, liver abscess

Pancreatic

Inflammatory: pancreatitis

Renal and urological

Inflammation: pyelonephritis, bladder infection, indigestion

Obstruction: kidney stones, urolithiasis, urinary retention, tumours

Vascular: left renal vein entrapment

Gynaecological or obstetric

Inflammatory: pelvic inflammatory disease

Mechanical: ovarian torsion

Endocrinological: menstruation, Mittelschmerz

Tumors: endometriosis, fibroids, ovarian cyst, ovarian cancer

Pregnancy: ruptured ectopic pregnancy, threatened abortion

Abdominal wall

muscle strain or trauma

muscular infection

neurogenic pain: herpes zoster, radiculitis in Lyme disease, abdominal cutaneous nerve entrapment syndrome (ACNES), tabes dorsalis

Referred pain

from the thorax: pneumonia, pulmonary embolism, ischemic heart disease, pericarditis

from the spine: radiculitis

from the genitals: testicular torsion

Metabolic disturbance

uremia, diabetic ketoacidosis, porphyria, C1-esterase inhibitor deficiency, adrenal insufficiency, lead poisoning, black widow spider bite, narcotic withdrawal

Blood vessels

aortic dissection, abdominal aortic aneurysm

Immune system

sarcoidosis

vasculitis

familial Mediterranean fever

Idiopathic

irritable bowel syndrome (affecting up to 20% of the population, IBS is the most common cause of recurrent, intermittent abdominal pain)

Acute abdominal pain

Acute abdomen can be defined as severe, persistent abdominal pain of sudden onset that is likely to require surgical intervention to treat its cause. The pain may frequently be associated with nausea and vomiting, abdominal distention, fever and signs of shock. One of the most common conditions associated with acute abdominal pain is acute appendicitis.

Selected causes of acute abdomen

Traumatic: blunt or perforating trauma to the stomach, bowel, spleen, liver, or kidney

Inflammatory:

Infections such as appendicitis, cholecystitis, pancreatitis, pyelonephritis, pelvic inflammatory disease, hepatitis, mesenteric adenitis, or a subdiaphragmatic abscess

Perforation of a peptic ulcer, a diverticulum, or the caecum

Complications of inflammatory bowel disease such as Crohn's disease or ulcerative colitis

Mechanical:

Small bowel obstruction secondary to adhesions caused by previous surgeries, intussusception, hernias, benign or malignant neoplasms

Large bowel obstruction caused by colorectal cancer, inflammatory bowel disease, volvulus, fecal impaction or hernia

Vascular: occlusive intestinal ischemia, usually caused by thromboembolism of the superior mesenteric artery

By location

Location

Upper middle abdominal pain

Stomach (gastritis, stomach ulcer, stomach cancer)

Pancreas pain (pancreatitis or pancreatic cancer, can radiate to the left side of the waist, back, and even shoulder)

Duodenal ulcer, diverticulitis

Appendicitis (starts here, after some time moves to lower right abdomen)

Upper right abdominal pain

Liver (caused by hepatomegaly due to fatty liver, hepatitis, or caused by liver cancer, abscess)

Gallbladder and biliary tract (gallstones, inflammation, roundworms)

Colon pain (below the area of liver – bowel obstruction, functional disorders, gas accumulation, spasm, inflammation, colon cancer)

Upper left abdominal pain

Spleen pain (splenomegaly)

Pancreas

Colon pain (below the area of spleen – bowel obstruction, functional disorders, gas accumulation, spasm, inflammation, colon cancer)

Middle abdominal pain (pain in the area around belly button)

Appendicitis (starts here)

Small intestine pain (inflammation, intestinal spasm, functional disorders)

Lower abdominal pain (diarrhea, colitis and dysentery)

Lower right abdominal pain

Cecum (intussusception, bowel obstruction)

Appendix point (Appendicitis location)

Lower left abdominal pain

diverticulitis, sigmoid volvulus, obstruction or gas accumulation

Pelvic pain

bladder (cystitis, may be secondary to diverticulum and bladder stone, bladder cancer)

pain in women (uterus, ovaries, fallopian tubes)

Right lumbago and back pain

liver pain (hepatomegaly)

right kidney pain (its location below the area of liver pain)

Left lumbago and back pain

less in spleen pain

left kidney pain

Low back pain

kidney pain (kidney stone, kidney cancer, hydronephrosis)

Ureteral stone pain

Diagnostic approach

When a health care practitioner assesses a patient to determine the etiology and subsequent treatment for abdominal pain the history of the presenting complaint and physical examination should derive a diagnosis in over 90% of cases.

Investigations that aid diagnosis include

Blood tests including full blood count, electrolytes, urea, creatinine, liver function tests, pregnancy test, amylase and lipase.

Urinalysis

Imaging including erect chest X-ray and plain films of the abdomen

An electrocardiograph to rule out a heart attack which can occasionally present as abdominal pain

If diagnosis remains unclear after history, examination and basic investigations as above then more advanced investigations may reveal a diagnosis. These as such would include

Computed tomography of the abdomen/pelvis

Abdominal or pelvic ultrasound

Endoscopy and colonoscopy (not used for diagnosing acute pain)

Management

Butylscopolamine (Buscopan) is used to treat cramping abdominal pain with some success.

Epidemiology

Abdominal pain is the reason about 3% of adults see their family physician. Rates of emergency department visits in the United States for abdominal pain increased 18% from 2006 through 2011. This was the largest increase out of 20 common conditions seen in the ED. The rate of ED use for nausea and vomiting also increased 18%.