Chronic abdominal pain in adults is defined as pain that persists for more than three months. This condition affects a significant portion of the adult population, with an estimated incidence of 15-25%. Chronic abdominal pain is important because it can significantly impact a person’s quality of life, daily functioning, and psychological well-being. Moreover, it can be a symptom of various underlying conditions, some of which may be serious and require timely medical intervention.
The anatomy of abdominal pain
Being familiar with the anatomy of the abdomen is important for understanding the causes and mechanisms of chronic abdominal pain. The following is a list of the organs and structures within the abdomen, their locations, functions, and how each can contribute to abdominal pain:
- Stomach: The stomach is located in the upper part of the abdomen and is responsible for digesting food. Pain originating from the stomach is often due to conditions like gastritis, which causes inflammation of the stomach lining, or ulcers, which are open sores on the stomach’s lining.
- Liver: The liver is situated in the right upper quadrant of the abdomen. It detoxifies substances and produces bile, which aids in digestion. Liver diseases such as hepatitis can cause abdominal pain by inflaming the liver tissue.
- Gallbladder: The gallbladder is found beneath the liver and stores bile produced by the liver. Conditions like gallstones can block the bile ducts, causing intense pain known as biliary colic, which typically occurs in the right upper quadrant.
- Pancreas: The pancreas is located behind the stomach and secretes digestive enzymes and hormones like insulin. Pancreatitis, or inflammation of the pancreas, can result in severe abdominal pain that often radiates to the back.
- Small intestine: The small intestine is coiled in the middle of the abdomen and is responsible for absorbing nutrients from digested food. Conditions such as Crohn’s disease, which causes chronic inflammation, can lead to pain in the small intestine.
- Large intestine: The large intestine encircles the small intestine and absorbs water from digested food, forming stool. Irritable bowel syndrome (IBS) and diverticulitis, which is the inflammation of pouches in the colon wall, can cause significant pain in this area.
- Appendix: The appendix is attached to the large intestine in the lower right quadrant of the abdomen. When the appendix becomes inflamed, a condition known as appendicitis, it causes severe pain that typically begins near the navel and shifts to the lower right abdomen.
- Kidneys: The kidneys are located on either side of the back and filter blood to produce urine. Kidney stones can cause severe flank pain that may radiate to the lower abdomen.
- Spleen: The spleen is situated in the left upper quadrant of the abdomen. It filters blood and supports the immune system. Conditions such as splenomegaly and an enlargement of the spleen can cause pain in this area.
What is the most common cause of chronic abdominal pain in adults?
Irritable bowel syndrome (IBS)
Irritable bowel syndrome (IBS) is the most common cause of chronic abdominal pain in adults. IBS is a functional gastrointestinal disorder characterized by abnormal gut motility and increased visceral sensitivity. It affects approximately 10-15% of adults and commonly presents between the ages of 20 and 50. Distinguishing features include recurrent abdominal pain associated with altered bowel habits, such as diarrhea, constipation, or both. The pain is often described as crampy or achy and is typically relieved by defecation. Additional symptoms include bloating and discomfort. Diagnostic clues are based on symptom patterns over time, using criteria such as Rome IV. Treatment includes dietary adjustments, fiber supplements, antispasmodic medications, and psychological therapies.
Other common medical conditions associated with chronic abdominal pain in adults
Functional dyspepsia
Functional dyspepsia is characterized by chronic upper abdominal discomfort without an identifiable cause. It affects adults of all ages and presents with symptoms such as bloating, nausea, and early satiety. The pain is typically described as a burning or gnawing sensation. Diagnosis is made after ruling out other conditions, and treatment includes dietary changes and medications to reduce stomach acid.
Gastritis
Gastritis, or inflammation of the stomach lining, is a very common cause of chronic abdominal pain. It is often due to H. pylori infection or prolonged use of NSAIDs. Symptoms include upper abdominal pain and nausea, with the pain often described as burning or gnawing. Diagnosis involves endoscopy and biopsy, with treatment focusing on eradicating H. pylori and avoiding NSAIDs.
Medications
Medications, particularly NSAIDs, can contribute to chronic abdominal pain. These medications can irritate the stomach lining, leading to conditions such as gastritis or peptic ulcers. The pain is typically described as a burning or gnawing sensation. Some medications can also cause pain by slowing down the stomach or preventing the stomach from functioning normally. Management involves discontinuing the offending medication and using alternatives that are less irritating to the stomach.
Gastroesophageal reflux disease (GERD)
Gastroesophageal reflux disease (GERD) is a frequent cause of chronic abdominal pain. GERD occurs when stomach acid frequently flows back into the esophagus, leading to symptoms such as heartburn and regurgitation. The pain is typically described as a burning sensation in the upper abdomen or chest. It affects individuals of all ages but is more common in adults over 40. Diagnostic clues include symptom relief with antacids and endoscopic evidence of esophagitis. Treatment typically involves lifestyle changes and proton pump inhibitors.
Disordered motility
Disordered motility secondary to conditions such as diabetes can cause chronic abdominal pain. Gastroparesis, a condition where the stomach empties slowly, can lead to symptoms such as bloating, nausea, and abdominal discomfort. The pain is often described as a feeling of fullness or pressure. Diagnosis involves gastric emptying studies, and treatment focuses on dietary changes and medications to improve gastric motility.
Cholecystitis
Cholecystitis or chronic inflammation of the gallbladder can cause persistent right upper quadrant pain that is worse after eating a fatty meal. It is typically often due to gallstones. The pain is typically described as a steady, aching sensation. It is diagnosed through imaging studies such as ultrasound and treated with antibiotics and sometimes cholecystectomy.
Diverticular disease
Diverticular disease involves the formation of pouches in the colon wall that can become inflamed, leading to chronic abdominal pain. The pain is typically localized to the left lower quadrant and is described as a crampy or achy sensation. It is more common in adults over 50. Diagnosis involves imaging studies such as CT scans, and treatment includes dietary modifications and antibiotics for inflammation.
Peptic ulcer disease
Peptic ulcer disease is a chronic condition involving recurrent sores in the stomach lining, often due to H. pylori infection or NSAID use. It typically affects adults over 50, presenting with persistent upper abdominal pain that may be described as burning or gnawing. Endoscopy and H. pylori testing aid diagnosis, and treatment includes acid suppression and H. pylori eradication.
Chronic constipation
Chronic constipation, more common in older adults, involves persistent difficulty in bowel movements. Symptoms include bloating and straining, with the pain often described as a feeling of fullness or pressure in the abdomen. Diagnosis is based on symptom history and physical examination, with treatment focusing on dietary fiber, laxatives, and hydration.
Celiac disease
Celiac disease is an autoimmune response to gluten, typically diagnosed in adults aged 30-50. Symptoms include diarrhea, weight loss, and abdominal pain, which is often crampy and related to the ingestion of gluten-containing foods. Diagnosis involves serology and biopsy, and treatment requires a strict gluten-free diet.
Lactose intolerance
Lactose intolerance results from the inability to digest lactose, a sugar found in milk and dairy products. It can cause bloating, diarrhea, and abdominal discomfort, which is often crampy and occurs after consuming dairy. Diagnosis is often based on symptom relief after eliminating lactose from the diet, and treatment involves dietary modifications.
Chronic pancreatitis
Chronic pancreatitis results from long-term inflammation of the pancreas and often affects adults aged 30-60. The pain associated with chronic pancreatitis is usually a persistent, dull ache that can radiate to the back. Additional symptoms include steatorrhea and weight loss. Imaging studies can help diagnose this condition, and treatment involves enzyme supplements and pain management.
Inflammatory bowel disease (IBD)
Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, causes chronic inflammation of the gastrointestinal tract. It commonly presents in late adolescence or early adulthood and includes symptoms such as diarrhea, weight loss, and abdominal pain. The pain is often crampy and can be localized to different parts of the abdomen, depending on the affected areas. Endoscopy and biopsy are diagnostic tools, and treatment involves anti-inflammatory drugs and immunosuppressants.
Endometriosis
Endometriosis involves the growth of endometrial tissue outside the uterus. Over time, this can lead to chronic abdominal or pelvic pain. The pain associated with endometriosis can be sharp, crampy, or constant and is often worse during menstruation. It affects women of reproductive age and is diagnosed through laparoscopy. Treatment options include hormonal therapy and surgery.
Chronic hepatitis
Chronic hepatitis, often due to viral infections or alcohol abuse, causes long-term liver inflammation. Adults aged 30-60 are commonly affected, presenting with symptoms such as jaundice and liver dysfunction. The pain is typically a dull ache in the right upper quadrant. Diagnosis involves liver function tests and serology, with treatment focusing on antiviral therapy and lifestyle changes.
Pelvic inflammatory disease (PID)
Pelvic inflammatory disease (PID) results from infection of the female reproductive organs and affects sexually active women aged 15-44. Symptoms include lower abdominal pain and fever, with the pain often described as sharp or crampy. Diagnosis involves a pelvic exam and ultrasound, with treatment involving antibiotics and sometimes surgery.
Mittelschmerz
Mittelschmerz, or ovulation pain, is a common cause of chronic lower abdominal pain in women. It occurs mid-cycle when an egg is released from the ovary. The pain is typically mild and crampy and resolves on its own. The timing of the pain determines the diagnosis, and treatment is usually not necessary.
Less common but serious medical conditions associated with chronic abdominal pain in adults
Mesenteric ischemia
Mesenteric ischemia, or decreased blood flow to the intestines, can cause chronic postprandial pain and weight loss. It is more common in older adults. The pain is often described as crampy and is associated with eating. Diagnosis involves angiography and imaging studies, and treatment includes revascularization and anticoagulation.
Volvulus
Volvulus, the twisting of a part of the intestine causing obstruction, can result in severe chronic abdominal pain. It is more common in older adults. The pain is typically described as crampy and may be associated with vomiting and distension. Diagnosis involves an X-ray or CT scan, and treatment includes endoscopic detorsion and surgery.
Angina
Angina, resulting from decreased blood flow to the heart, can sometimes present as chronic abdominal pain. It typically affects older adults with a history of cardiovascular disease. The pain is often described as a pressure or tightness in the chest that may radiate to the abdomen. Diagnosis involves cardiac testing such as stress tests and angiography, and treatment includes medications and lifestyle modifications.
Aortic aneurysm
Aortic aneurysm, an abnormal bulging of the aorta, is a serious condition that can cause chronic abdominal pain. It typically affects adults over 60 and may present with a pulsating abdominal mass. The pain is often described as a deep, constant ache that can radiate to the back. Diagnosis involves ultrasound or CT scan, and treatment includes monitoring and surgical repair.
Pancreatic cancer
Pancreatic cancer, a malignant tumor of the pancreas, often presents with chronic abdominal pain, weight loss, and jaundice. It commonly affects adults over 60. The pain is typically described as a dull ache that may radiate to the back. Diagnosis involves imaging and biopsy, and treatment includes surgery, chemotherapy, and radiation.
How does the location of the pain aid in the differential diagnosis?
Right upper quadrant
- Chronic cholecystitis involves long-term inflammation of the gallbladder, often due to gallstones, which can cause chronic right upper quadrant pain. The pain is typically described as a steady, aching sensation made worse by consuming fatty meals.
- Liver disease, including conditions such as hepatitis and cirrhosis, can also present with pain in this area, often described as a dull ache.
- Chronic pancreatitis, characterized by inflammation of the pancreas, may cause pain that radiates to the back and is described as a persistent, dull ache.
- Right kidney stones can lead to flank pain that extends to the right upper quadrant and is often described as sharp and severe.
- Hepatitis, an inflammation of the liver, is another potential cause of pain in this region. It typically presents as a dull ache.
Right lower quadrant
- Chronic appendicitis, or inflammation of the appendix that persists over time, can cause right lower quadrant pain. The pain is often described as a sharp or crampy sensation.
- Crohn’s disease, a type of inflammatory bowel disease, may also present with pain in this area, often described as crampy and associated with diarrhea.
- Right ovarian cysts, which are fluid-filled sacs on the ovary, can cause chronic pelvic pain described as a dull ache.
- Endometriosis, the growth of endometrial tissue outside the uterus, can lead to pain in the right lower quadrant, often described as sharp or crampy and worse during menstruation.
- IBS can cause abdominal pain that is often localized to this area and is typically described as crampy or achy.
Left upper quadrant
- Splenomegaly, an enlargement of the spleen, can cause chronic left upper quadrant pain, which is described as a dull ache or fullness.
- Gastric ulcers, sores on the stomach lining, may also cause pain in this region, often described as a burning or gnawing sensation.
- Chronic pancreatitis can cause left upper quadrant pain that radiates to the back and is described as a persistent, dull ache.
- Left kidney stones can lead to flank pain that extends to the left upper quadrant and is often described as sharp and severe.
- Colitis or inflammation of the colon can also cause pain in this area. It is typically described as crampy.
Left lower quadrant
- Diverticulitis, an inflammation of pouches within the colon wall, commonly causes pain in the left lower quadrant, which is described as crampy or achy.
- Ulcerative colitis, a chronic inflammatory condition of the colon, may also present with pain in this area, often described as crampy and associated with diarrhea.
- Left ovarian cysts can cause chronic pelvic pain localized to the left lower quadrant and described as a dull ache.
- IBS can cause abdominal pain that is often localized to this area and is typically described as crampy or achy.
- Endometriosis can also lead to pain in the left lower quadrant, often described as sharp or crampy and worse during menstruation.
Middle abdomen
- IBS is a common cause of chronic middle abdominal pain, typically described as crampy or achy.
- Chronic pancreatitis can cause pain that radiates from the middle abdomen to the back, often described as a persistent, dull ache.
- An aortic aneurysm, an abnormal bulging of the aorta, may present with central abdominal pain described as a deep, constant ache.
- Small bowel obstruction, a blockage in the small intestine, can cause pain in the middle abdomen described as crampy and associated with vomiting and distension.
- Chronic gastritis, an inflammation of the stomach lining, can also present with pain in this region, often described as burning or gnawing.
Clues to aid in the differential diagnosis
- Fever: Fever indicates infection or inflammation, such as appendicitis, diverticulitis, or inflammatory bowel disease. Fever is often accompanied by other signs of infection, such as an elevated white blood cell count.
- Jaundice: Jaundice suggests possible liver or bile duct disease like gallstones, hepatitis, or pancreatic cancer. Jaundice results from the accumulation of bilirubin in the blood, giving a yellowish tint to the skin and eyes.
- Vomiting: Vomiting is common in gastrointestinal obstruction, pancreatitis, and severe gastritis. Vomiting can lead to dehydration and electrolyte imbalances, further complicating the diagnosis.
- Hematuria: Hematuria, the presence of blood in the urine, may indicate urinary tract involvement, such as a UTI, kidney stones, or bladder cancer. It can also be a sign of significant pathology in the urinary system.
- Bloody stool: Blood in stool suggests gastrointestinal bleeding from peptic ulcer, colorectal cancer, or inflammatory bowel disease. Depending on the source of the bleeding, blood in the stool can appear as bright red or black, tarry stools.
- Weight loss: Weight loss is concerning for malignancies such as pancreatic cancer, gastrointestinal cancers, or chronic infections. Unintended weight loss is often a sign of a serious underlying condition that requires further investigation.
- Bloating: Bloating is often associated with IBS, chronic constipation, or gastroparesis. Bloating can be caused by the accumulation of gas or fluid in the abdomen, leading to a sensation of fullness and discomfort.
- Pain radiating to the back: Radiating pain to the back may indicate pancreatitis, gallstones, or aortic aneurysm. Radiating pain can help localize the source of the pain to specific organs or structures.
- Altered bowel habits: Altered bowel habits are common in IBS, colorectal cancer, and IBD. Changes in bowel habits, such as diarrhea or constipation, can provide important clues to the underlying cause of chronic abdominal pain.
Advice for patients
An adult with chronic abdominal pain should see a doctor if the pain is persistent, severe, or associated with additional symptoms such as fever, jaundice, recurrent vomiting, blood in stool, or significant weight loss. Treatment and management depend on the underlying cause, which may range from dietary changes and medications for IBS to surgery for appendicitis or aortic aneurysm. It is important to seek medical care for symptoms indicative of serious conditions, such as severe pain, signs of infection, or gastrointestinal bleeding.
Summary
Chronic abdominal pain in adults is a common and complex condition with numerous potential causes. While most cases of chronic abdominal pain result from functional, non-life-threatening causes such as irritable bowel syndrome, other more serious conditions should be ruled out when symptoms persist despite treatment or when red-flag symptoms such as jaundice, weight loss and bloody stools are also present.