Causes of Abdominal Pain – Diagnosis from Symptoms and Investigations

How to Determine a Cause of Abdominal Pain

The cause of abdominal (stomach) pain can be determined from:


  • Right upper quadrant (RUQ) pain may be from gallstones, bile ducts dysfunction, liver diseases, right kidney or ureteral disorders or right adrenal gland
  • Left upper quadrant (LUQ) pain may be from to pancreatitis or pancreatic cancer, spleen enlargement or rupture, trapped gas in the colon, left kidney or ureteral disorders, or left adrenal gland
  • Upper middle abdominal pain may be from gastritis, stomach or duodenal ulcer or cancer, pancreatitis or pancreatic cancer, aortic aneurysm or dissection of abdominal aorta, lymph nodes enlargement in lymphoma or strained or injured muscles of abdominal wall
  • Right lower quadrant (RLQ) pain may be from appendicitis, right colon inflammation in Crohn’s disease, right ovarian cyst or cancer or twisting, ectopic pregnancy, a stone in the right ureter, intestinal hernia.
  • Left lower quadrant (LLQ) pain may be from diverticulitis, atherosclerosis of abdominal arteries, left ovarian disorder, ectopic pregnancy, a stone in the left ureter, intestinal hernia.
  • Lower middle abdominal pain may arise from muscles of abdominal wall (stretching, injury, hypokalemia), menstruation, infection or cancer of the bladder, pelvic inflammatory disease, inflammation of urethra (mostly infection, including STDs), inflammation or cancer of the prostate, diseases of testes, epidydimis or seminal ducts.
  • Abdominal pain that is hard to locate may appear in constipation or IBS.
  • Diffuse abdominal pain may be from severe bloating or peritonitis.


  • Sudden onset (acute) abdominal pain.
  • Prolonged or recurring (chronic) abdominal pain.
  • Abdominal pain during or after the meal  may be from stomach ulcer, gastroparesis, IBS, food allergies
  • Night abdominal pain may appear in duodenal ulcer or spinal disorders.
  • Pain during the bowel movement may appear in constipation, diverticulitis, anal fissure, colorectal cancer or thrombosed hemorrhoids.
  • Severe debilitating abdominal pain may be a symptom of bowel obstruction or perforation, cancer of any abdominal organ, appendicitis or peritonitis.
  • Sharp cramping pain is usually from urinary stones in the kidney or ureter(s), or gallstones in the gallbladder or bile ducts.

3. Abdominal and other SYMPTOMS:

4. SIGNS, found by the doctor during physical examination (1):

  • Inspection. Paleness  may appear in anemia due to iron malabsorption or in chronic bowel bleeding. Skin rash may be present in hepatitis, celiac and Crohn’s disease. Jaundice and abdominal swelling speak for liver cirrhosis. Visible lumps are usually from enlarged liver or spleen or from intestinal hernia. Rectal mucosa may protrude out from anal canal in hemorrhoids or prolapsed rectumCracks and openings around the anus may be from fungi or Crohn’s disease. Bluish discoloration around the navel or in flanks speak for intra-abdominal bleeding (in severe pancreatitis, ectopic pregnancy or injury).
  • Palpation. Abdominal wall is locally tender in gallbladder disease (RUQ), appendicitis (RLQ) and tender all over and rigid in peritonitis (emergency!). Enlarged liver (RUQ) may be due to liver disease, congestive heart disease or lymphoma/leukemia. Enlarged spleen (LUQ) may appear in lymphoma/leukemia or in liver disease. Lumps are mostly due to abdominal or inguinal hernia or, rarely, due to benign tumors (fibroma) or cancer.
  • Percussion. By tapping with a finger on the swollen abdominal wall a doctor can distinguish among fluid (mostly in liver cirrhosis or in malnourished children in poor countries), gas and fat. Distended bladder can be also detected this way.
  • Auscultation (listening by stethoscope). Normally some sounds from usual moving of the stool and gas can be heard. Excessive sounds are heard in speeded peristalsis (usually in food poisoning) or in partial bowel obstruction. No sounds can be heard in severe constipation, in complete bowel obstruction – ileus and after abdominal surgery.
  • Digital rectal examination. A doctor can detect (with a gloved finger) a palpable mass that may represent colorectal polyp or carcinoma, inflamed prostate or prostatic cancer, pus collection (abscess, often in Crohn’s disease) or thrombosed hemorrhoids.


  • Stool tests may reveal harmful bacteria (in food poisoning or after antibiotic treatment), intestinal parasites, blood, excessive fats (chronic pancreatitis, stones in bile duct, celiac or Crohn’s disease), sugars (in fructose malabsorption in small children) and special antibodies (in celiac or Crohn’s disease).
  • Ultrasound may reveal big gallstones (> 2 mm), liver and spleen enlargement, urinary stones, pancreatic cyst or cancer, aneurysm of abdominal aortar and some other disorders.
  • Plain X-ray of the abdomen is usually the first investigation in severe abdominal pain. X-ray with barium swallow is regularly performed before upper endoscopy and X-ray with barium enema is performed before colonoscopy. Big stomach or intestinal tumors, deep ulcers, strictures (intestinal narrowings) and diverticles may be revealed this way.
  • CT of the abdomen is good to show small gallstones, changes in solid abdominal organs, tumors in the abdominal cavity but is not good to show small changes in the stomach or intestinal mucosa.
  • MRI of the abdomen may be done instead of CT. Special MRI investigations of bile ducts and abdominal arteries exist.
  • Upper endoscopy. Esophago-gastro-duodenoscopy (EGD) may reveal esophageal varices, inflammation or ulcers, gastritis, gastric ulcers or carcinoma, and duodenal inflammation and ulcers. With endoscopic retrograde cholangiopancreatography (ERCP) bile and pancreatic ducts can be checked.
  • Lower endoscopy: Rectoscopy, sigmoidoscopy and colonoscopy may reveal changes in mucosa of the large intestine. An end part of the small intestine can be checked with colonoscopy. Biopsy and hystologic examination of obtained sample under the microscope
  • Capsule endoscopy is performed when small intestinal disorders are expected. A patient swallows a small capsule with a camera that takes photos of small intestinal mucosa that can be later evaluated with the help of the computer.

Normal Abdomen Feeling

The abdomen feels firm but not rigid in fit and muscular people, and spongy in people with more abdominal fat and less developed abdominal muscles. Upon palpation (deep pressure with the hand), many organs and structures can be felt in the abdomen and may vary from firm to soft or spongy to touch.

There should be no pain or tenderness present even upon deep palpation, although mild discomfort may be noticed upon applying pressure on the suprapubic region  (hypogastrium) due to a full bladder or in the left iliac fossa due to the presence of hard feces, especially in a person who is constipated.

Normal Abdominal Mass (‘Lumps’)

Abdominal bloating (distension) may be due to a number of reasons but the most common causes include flatus (gas), fluid, feces, fetus (pregnancy) and fat (the 5 F’s) – refer to Swollen Stomach for more information. The following are the organs and structures that may normally be felt in the abdomen as a lump or mass.

Right upper quadrant

  • Liver – the edge of the liver may be felt next to the right ribcage and just below (inferior) to it.
  • Kidney – the lower pole of the right kidney may palpable immediately below the right ribcage.

Left upper quadrant

  • Colon – hard feces and trapped gas may be palpable just below and slight under the left ribcage. The colon itself may be felt all the way down the left side of the abdomen as this is the section of the colon where mushy colon contents becomes firmer.

Middle of the Abdomen
This includes the epigastrium (upper), umbilical (middle), hypogastrium (lower).

  • Upper – abdominal aorta (pulsating), distended stomach
  • Middle – rectus abdominus muscle, transverse colon (mushy contents of gas)
  • Lower – distended bladder (the position of the bladder can vary depending on whether it is filled or not and in children, the bladder is in the abdomen and has not as yet descended into the pelvis)

Right Lower Quadrant

  • Lymph nodes – inguinal lymph nodes
  • Colon – the colonic contents are usually fluid in this part of the colon

Left Lower Quadrant

  • Lymph nodes – inguinal lymph nodes
  • Colon – hard feces

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1. Abdominal examination  (

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