Abdominal Pain Differential Diagnosis
Causes of Abdominal Pain Based on Location:
The assessment of abdominal pain involves an understanding of the mechanisms responsible for pain, a wide differential of common causes, and recognition of classic patterns and clinical presentations. This article covers abdominal pain differential diagnosis.
Pathophysiology of abdominal pain:
— Neurologic basis for abdominal pain – Stretch is the primary mechanical stimulus of the visceral receptors located on serosal surfaces, within the mesentery, and within the walls of hollow viscera. Other mechanical stimulus distention, contraction, traction, compression, and torsion.
— Localization– The type and density of visceral afferent nerves makes the localization of visceral pain imprecise. Most digestive tract pain is observed in the midline because of bilaterally symmetric innervation. Pain that is clearly lateralized most likely arises from the ipsilateral kidney, ureter, ovary, or somatically innervated structures, which have predominantly unilateral innervation. Exceptions to this rule include the gallbladder and ascending and descending colons which, although bilaterally innervated, have predominant innervation located on their ipsilateral sides.
— Referred pain– Pain originating in the viscera may sometimes be perceived as originating from a site distant from the affected organ. Referred pain is usually located in the cutaneous dermatomes sharing the same spinal cord level as the visceral inputs. As an example, pain from an inflamed gallbladder may be perceived in the scapula.
RIGHT UPPER QUADRANT abdominal pain differential diagnosis:
Biliary and hepatic etiologies cause right upper quadrant pain syndromes.
— Biliary colic – also known as a gallbladder attack, is when pain occurs due to a gallstone temporarily blocking the bile duct. Symptoms include an intense, dull discomfort located in the right upper quadrant, that may radiate to the back (particularly the right shoulder blade). Patients may have associated nausea, vomiting, and diaphoresis.
— Acute cholangitis – Acute cholangitis occurs when a stone becomes impacted in the biliary or hepatic ducts, causing dilation of the obstructed duct and bacterial superinfection. It is characterized by Charcot’s triad, which includes fever, jaundice, and right upper quadrant abdominal pain.
— Sphincter of Oddi dysfunction – Sphincter of Oddi dysfunction can be a cause of biliary pain in the absence of gallstones or biliary inflammation. Typically the pain is located in the right upper quadrant or epigastrium and lasts from 30 minutes to several hours.
— Hepatitis – Patients with acute hepatitis (eg, from hepatitis A, alcohol, or medications) may have fatigue, malaise, nausea, vomiting, and anorexia in addition to right upper quadrant pain. Other symptoms include jaundice, light color stool and dark urine.
— Liver abscess – Liver abscess is the most common type of visceral abscess. Patients generally present with fever and abdominal pain. Risk factors include diabetes, underlying hepatobiliary or pancreatic disease, or liver transplant.
— Budd-Chiari syndrome – is an uncommon condition induced by thrombotic or nonthrombotic obstruction of the hepatic venous outflow. Symptoms include fever, abdominal pain, abdominal distention (from ascites), lower extremity edema, jaundice, gastrointestinal bleeding, and/or hepatic encephalopathy.
— Portal vein thrombosis – Clinical manifestations of portal vein thrombosis vary depending on the extent of obstruction as well as the speed of development (acute or chronic). It is common in patients with cirrhosis and is associated with the severity of liver disease. Patients may be asymptomatic or have abdominal pain, dyspepsia, or gastrointestinal bleeding.
LEFT UPPER QUADRANT Abdominal pain differential diagnosis:
Left upper quadrant pain is often related to the spleen.
— Splenomegaly – can cause left upper quadrant pain or discomfort, referred pain to the left shoulder, and/or early satiety.
— Splenic infarction – classically present with severe left upper quadrant pain and is associated with a variety of underlying conditions such as hypercoagulable state, embolic disease from atrial fibrillation, conditions associated with splenomegaly.
— Splenic abscess – Are uncommon and typically are associated with fever and tenderness in the left upper quadrant. They may also be associated with splenic infarction.
— Splenic rupture – Is most often associated with trauma. The patient may complain of left upper abdominal, left chest wall, or left shoulder pain (ie, Kehr’s sign).
EPIGASTRIC abdominal pain differential diagnosis:
Pancreatic and gastric etiologies often cause epigastric pain.
— Acute myocardial infarction – Epigastric pain can be the presenting symptom of an acute myocardial infarction. Patients may have associated shortness of breath or exertional symptoms.
— Acute Pancreatitis – Both acute and chronic pancreatitis are associated with abdominal pain that often radiates to the back. Most patients with acute pancreatitis have acute onset of persistent, severe epigastric pain.
— Peptic ulcer disease (PUD) – Upper abdominal pain or discomfort is the most prominent symptom in patients with peptic ulcers.
— Gastroesophageal reflux disease (GERD) – Most patients with GERD complain of heartburn, regurgitation, and dysphagia. However, some patients may also complain of epigastric and/or chest pain.
— Gastritis – refers to inflammation in the lining of the stomach. Gastritis is predominantly an inflammatory process, while the term gastropathy denotes a gastric mucosal disorder with minimal to no inflammation. Acute gastropathy often presents with abdominal discomfort/pain, heartburn, nausea, vomiting, and hematemesis. Gastropathy may be caused by a variety of etiologies including alcohol and NSAIDs.
— Functional dyspepsia – Is defined as the presence of one or more of the following symptoms: postprandial fullness, early satiation, and epigastric pain or burning, with no evidence of structural disease (including at upper endoscopy) to explain the symptoms.
— Gastroparesis – can present with nausea, vomiting, abdominal pain, early satiety, postprandial fullness, bloating, and, in severe cases, weight loss. The most common causes are idiopathic, diabetic, or postsurgical.
LOWER abdominal pain differential diagnosis:
Lower abdominal pain syndromes often cause pain in either or both lower quadrants. Women may have lower abdominal pain from disorders of the internal female reproductive organs.
Lower abdominal pain syndromes that are generally localized to ONE SIDE include:
— Acute appendicitis – Typically presents with periumbilical pain initially that radiates to the right lower quadrant. It is associated with anorexia, nausea, and vomiting. Acute appendicitis can be clinically diagnosed through specific physical examinations including Rovsing’s Sign, Obturator Sign, and the Psoas Sign.
— Diverticulitis – Left lower quadrant pain is the most common complaint. The pain is usually constant and is often present for several days prior to presentation. Patients may also have nausea and vomiting.
Lower abdominal pain from some genitourinary etiologies may be localized to EITHER SIDES:
— Kidney stones – usually cause symptoms when the stone passes from the renal pelvis into the ureter. Pain is the most common symptom and varies from a mild to severe. Patients may have flank pain, back pain, abdominal pain and hematuria.
— Pyelonephritis – Patients may or may not have symptoms of cystitis (dysuria, frequency, urgency, and/or hematuria). These patients also have fever, chills, flank pain, and costovertebral angle tenderness.
— Ovarian torsion – Acute onset of moderate to severe pelvic pain, often with nausea and possibly vomiting, in a woman with an adnexal mass.
— Ectopic pregnancy – Unilateral lower abdominal pain. Positive pregnancy test. Normal pregnancy discomforts (eg, breast tenderness, frequent urination, nausea) are sometimes present.
Other etiologies of lower abdominal pain may not always be localized to one side:
— Cystitis – Patients with cystitis may complain of suprapubic pain as well as dysuria, frequency, urgency, and/or hematuria.
— Infectious colitis – Patients generally have diarrhea as the predominant symptom but may also have associated abdominal pain, which may be severe.
— Pelvic inflammatory disease (PID) – acute and subclinical infection of the upper genital tract in women, involving any or all of the uterus, fallopian tubes, and ovaries. Caused by sexually transmitted pathogens. Associated with bilateral lower abdominal pain and cervical motion, uterine, or adnexal tenderness.
DIFFUSE abdominal pain differential diagnosis:
Abdominal pain syndromes may have diffuse, non-specific abdominal or variable presentations of pain:
— Obstruction – Severe, acute diffuse abdominal pain can be caused by either partial or complete obstruction of the intestines. Intestinal obstruction should be considered when the patient complains of pain, vomiting, and obstipation. Physical findings include abdominal distention, tenderness to palpation, high-pitched or absent bowel sounds, and a tympanic abdomen. The most common etiologies in adults being postoperative adhesions, malignancy related (eg, from colorectal cancer), and complicated hernias. Other less common etiologies include Crohn disease, gallstones, volvulus, and intussusception.
— Perforation of gastrointestinal tract – Can present acutely or in an indolent manner. Sudden, severe chest or abdominal pain following instrumentation or surgery is very concerning for perforation.
— Mesenteric ischemia – Acute mesenteric ischemia presents with the acute and severe onset of diffuse and persistent abdominal pain, often described as pain out of proportion to examination.
— Inflammatory bowel disease (IBD) – IBD is comprised of two major disorders: ulcerative colitis and Crohn’s disease.
— Ulcerative colitis (UC) – Usually present with diarrhea which may be associated with blood. Bowel movements are frequent and small in volume as a result of rectal inflammation. Associated symptoms include colicky abdominal pain, urgency, tenesmus, and incontinence.
— Crohn’s disease (CD) – Fatigue, prolonged diarrhea with abdominal pain, weight loss, and fever, with or without gross bleeding, are the hallmarks of CD.
— Spontaneous bacterial peritonitis (SBP) – Most often occurs in cirrhotics with advanced liver disease with ascites. Patients present with fever, abdominal pain, and/or altered mental status.
— Malignancy – Gastrointestinal malignancies may be associated with abdominal discomfort. For example; colorectal cancer, gastric cancer, pancreatic cancer.
— Celiac disease – Patients with celiac disease may complain of abdominal pain in addition to diarrhea with bulky, foul-smelling, floating stools due to steatorrhea and flatulence.
— Ketoacidosis – Patients with ketoacidosis (eg, from diabetes or alcohol) may have diffuse abdominal pain as well as nausea and vomiting.
— Adrenal insufficiency – Patients with adrenal insufficiency may have diffuse abdominal pain as well as nausea and vomiting. Patients with adrenal crisis may present with shock and hypotension.
— Irritable bowel syndrome (IBS) – Present with chronic abdominal pain and altered bowel habits.
— Constipation – Constipation may be associated with abdominal pain. Diseases associated with constipation include neurologic and metabolic disorders, obstructing lesions of the gastrointestinal tract, including colorectal cancer, endocrine disorders such as diabetes mellitus, and psychiatric disorders such as anorexia nervosa.
— Diverticulosis – Uncomplicated diverticulosis is often asymptomatic and an incidental finding on colonoscopy or sigmoidoscopy. However, these patients may have symptoms of abdominal pain and constipation.
— Lactose intolerance – Symptoms of lactose intolerance include abdominal pain, bloating, flatulence, and diarrhea. The abdominal pain may be cramping in nature and is often localized to the periumbilical area or lower quadrants.