Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Since the abdomen contains most of the body's vital organs, it can be an indicator of a wide variety of diseases. Given that, approaching the examination of a person and planning of a differential diagnosis is extremely important.
Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a more serious underlying condition such as appendicitis, leaking or ruptured abdominal aortic aneurysm, diverticulitis, or ectopic pregnancy. In a third of cases, the exact cause is unclear.
Signs and symptoms The onset of abdominal pain can be abrupt, quick, or gradual. Sudden onset pain happens nearly instantaneously. Rapidly onset pain starts mild and gets worse over the next few minutes. Pain that gradually intensifies only after several hours or even days has passed is referred to as gradual onset pain.
One can describe abdominal pain as either continuous or sporadic and as cramping, dull, or aching. The characteristic of cramping abdominal pain is that it comes in brief waves, builds to a peak, and then abruptly stops for a period during which there is no more pain. The pain flares up and off periodically. The most common cause of persistent dull or aching abdominal pain is edema or distention of the wall of a hollow viscus. A dull or aching pain may also be felt due to a stretch in the liver and spleen capsules.
Causes The most frequent reasons 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 (gallstones or biliary dyskinesia) or pancreas problems (4%), diverticulitis (3%), appendicitis (2%) and cancer (1%). More common in those who are older, ischemic colitis, mesenteric ischemia, and abdominal aortic aneurysms are other serious causes.
Acute abdomen Acute abdomen is a condition where there is a sudden onset of severe abdominal pain requiring immediate recognition and management of the underlying cause. The underlying cause may involve infection, inflammation, vascular occlusion or bowel obstruction.
The pain may elicit nausea and vomiting, abdominal distention, fever and signs of shock. A common condition associated with acute abdominal pain is appendicitis. Here is a list of acute abdomen causes: Surgical causesSource:
Inflammatory Infections such as appendicitis, cholecystitis, pancreatitis, pyelonephritis, Peritonitis, 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.
Referred pain Source: Viscero-visceral referral: happens when one organ with afferent nerves close to another organ is sensitized or inflamed (in this case any of the abdominal viscera) Viscero-somatic referral: any pain in the viscera that causes pain in the muscle, bone, and skin (of the abdomen in case of abdominal pain) Somatic-visceral referral: pain in the skin, muscles, and bone that causes referred pain in the viscera (of the abdomen such as the stomach, kidneys, bladder, etc.)Medical causesSource:
Acute pancreatitis.
Sickle cell anemia.
Diabetic ketoacidosis (DKA).
Adrenal crisis.
Pyelonephritis.
Lead poisoning.
Familial Mediterranean fever (FMF).Gynecological causesSource:
Pelvic inflammatory disease (PID) and abscess.
Ectopic pregnancy.
Hemorrhagic ovarian cyst.
Adnexal or ovarian torsion.
By system 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, tumors, 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, celiac disease, food allergies, indigestion Glands Bile system Inflammatory: cholecystitis, cholangitis Obstruction: cholelithiasis Liver Inflammatory: hepatitis, liver abscess Pancreatic Inflammatory: pancreatitis Renal and urological Inflammation: pyelonephritis, bladder infection Obstruction: kidney stones, urolithiasis, urinary retention 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 (IBS) (affecting up to 20% of the population, IBS is the most common cause of recurrent and intermittent abdominal pain)
By location The location of abdominal pain can provide information about what may be causing the pain. The abdomen can be divided into four regions called quadrants. Locations and associated conditions include: Diffuse Peritonitis Vascular: mesenteric ischemia, ischemic colitis, Henoch-Schonlein purpura, sickle cell disease, systemic lupus erythematosus, polyarteritis nodosa Small bowel obstruction Irritable bowel syndrome Metabolic disorders: ketoacidosis, porphyria, familial Mediterranean fever, adrenal crisis Epigastric Heart: myocardial infarction, pericarditis Stomach: gastritis, stomach ulcer, stomach cancer Pancreas: pancreatitis, pancreatic cancer Intestinal: duodenal ulcer, diverticulitis, appendicitis Right upper quadrant Liver: hepatomegaly, fatty liver, hepatitis, liver cancer, abscess Gallbladder and biliary tract: inflammation, gallstones, worm infection, cholangitis Colon: bowel obstruction, functional disorders, gas accumulation, spasm, inflammation, colon cancer Other: pneumonia, Fitz-Hugh-Curtis syndrome Left upper quadrant Splenomegaly Colon: bowel obstruction, functional disorders, gas accumulation, spasm, inflammation, colon cancer Peri-umbilical (the area around the umbilicus, i.e., the belly button) Appendicitis Pancreatitis Inferior myocardial infarction Peptic ulcer Diabetic ketoacidosis Vascular: aortic dissection, aortic rupture Bowel: mesenteric ischemia, Celiac disease, inflammation, intestinal spasm, functional disorders, small bowel obstruction Lower abdominal pain Diarrhea Colitis Crohn's Dysentery Hernia Right lower quadrant Colon: intussusception, bowel obstruction, appendicitis (McBurney's point) Renal: kidney stone (nephrolithiasis), pyelonephritis Pelvic: cystitis, bladder stone, bladder cancer, pelvic inflammatory disease, pelvic pain syndrome Gynecologic: endometriosis, intrauterine pregnancy, ectopic pregnancy, ovarian cyst, ovarian torsion, fibroid (leiomyoma), abscess, ovarian cancer, endometrial cancer Left lower quadrant Bowel: diverticulitis, sigmoid colon volvulus, bowel obstruction, gas accumulation, Toxic megacolon Right low back pain Liver: hepatomegaly Kidney: kidney stone (nephrolithiasis), complicated urinary tract infection Left low back pain Spleen Kidney: kidney stone (nephrolithiasis), complicated urinary tract infection Low back pain Kidney pain (kidney stone, kidney cancer, hydronephrosis) Ureteral stone pain
Mechanism RegionBlood supplyInnervationStructuresForegutCeliac arteryT5 - T9Pharynx Esophagus
Lower respiratory tract
Stomach
Proximal duodenum
Liver
Biliary tract
Gallbladder
PancreasMidgutSuperior mesenteric arteryT10 – T12Distal duodenum Cecum
Appendix
Ascending colon
Proximal transverse colonHindgutInferior mesenteric arteryL1 – L3Distal transverse colon Descending colon
Sigmoid colon
Rectum
Superior anal canal Abdominal pain can be referred to as visceral pain or peritoneal pain. The contents of the abdomen can be divided into the foregut, midgut, and hindgut. The foregut contains the pharynx, lower respiratory tract, portions of the esophagus, stomach, portions of the duodenum (proximal), liver, biliary tract (including the gallbladder and bile ducts), and the pancreas. The midgut contains portions of the duodenum (distal), cecum, appendix, ascending colon, and first half of the transverse colon. The hindgut contains the distal half of the transverse colon, descending colon, sigmoid colon, rectum, and superior anal canal.
Each subsection of the gut has an associated visceral afferent nerve that transmits sensory information from the viscera to the spinal cord. The visceral sensory information from the gut traveling to the spinal cord, termed the visceral afferent, is non-specific and overlaps with the somatic afferent nerves, which are very specific. Therefore, visceral afferent information traveling to the spinal cord can present in the distribution of the somatic afferent nerve; this is why appendicitis initially presents with T10 periumbilical pain when it first begins and becomes T12 pain as the abdominal wall peritoneum (which is rich with somatic afferent nerves) is involved.
Diagnosis A thorough patient history and physical examination is used to better understand the underlying cause of abdominal pain.
The process of gathering a history may include: Obtaining more information about the chief complaint including the history of present illness; i.e. a narrative of the current symptoms such as the onset, location, duration, character, aggravating or relieving factors, and temporal nature of the pain. Identifying other possible factors may aid in the diagnosis of the underlying cause of abdominal pain, such as recent travel, recent contact with other ill individuals, and for females, a thorough gynecologic history. Learning about the patient's past medical history, focusing on any prior issues or surgical procedures. Clarifying the patient's current medication regimen, including prescriptions, over-the-counter medications, and supplements. Confirming the patient's drug and food allergies. Discussing with the patient any family history of disease processes, focusing on conditions that might resemble the patient's current presentation. Discussing with the patient any health-related behaviors (e.g. tobacco use, alcohol consumption, drug use, and sexual activity) that might make certain diagnoses more likely. Reviewing the presence of non-abdominal symptoms (e.g., fever, chills, chest pain, shortness of breath, vaginal bleeding) that can further clarify the diagnostic picture. Using Carnett's sign to differentiate between visceral pain and pain originating in the muscles of the abdominal wall.