Summary
Classification
Epidemiology
Urgent Considerations
Etiology
Classification by location
- Gastrointestinal (GI) tract: hollow organs
- Esophagus: esophagitis (e.g., GERD); drug-induced (e.g., bisphosphonate, erythromycin); motility disorders (e.g., atypical achalasia); esophageal cancer
- Stomach: chronic gastritis (e.g., Helicobacter pylori); drug/alcohol-induced; peptic ulcer disease; gastric cancer
- Small bowel: inflammation (e.g., Crohn disease); drug-induced (e.g., aspirin, nonsteroidal anti-inflammatory drug [NSAID]); subacute obstruction (e.g., volvulus, intussusception)
- Large bowel: inflammation (e.g., ulcerative colitis, Crohn colitis, infectious gastroenteritis); subacute obstruction (e.g., volvulus, tumor); colorectal cancer
- GI tract: solid organs
- Liver: hepatocellular carcinoma, metastasis, abscesses
- Pancreas: chronic pancreatitis, pancreatic cysts/pseudocysts
- Gallbladder: cholecystitis, cholelithiasis
- Urogenital tract
- Kidneys/ureter/bladder: nephrolithiasis, pyelonephritis, perinephric abscess
- Female gynecologic diseases within the abdomen: endometriosis
- Abdominal vasculature
- Chronic mesenteric ischemia/intestinal ischemia/abdominal angina
- Superior mesenteric syndrome
- Pelvis
- Chronic pelvic pain (CPP) (e.g., interstitial cystitis, endometriosis, adhesions, urethral syndrome, changes or dysfunction of the pelvic muscles)[19]
- Female genitalia and reproductive organs (e.g., pelvic inflammatory disease [PID], endometriosis, ovarian cystic diseases, gynecologic malignancies)
- Male genitalia and reproductive organs (e.g., prostatitis, prostate cancer, epididymitis, intermittent/recurrent torsion of testicle)[20]
- Chest/thorax
- Lungs (e.g., malignancy)
- Pleura and chest wall
- Musculoskeletal
- Abdominal wall (e.g., abdominal cutaneous nerve entrapment syndrome, abdominal wall hernia)[21]
- Spine (e.g., radiculitis)
- Neurogenic causes
- Herpes zoster
- Celiac disease
- Lactose intolerance/lactase deficiency
- Drugs: narcotics, non-dihydropyridine calcium-channel blockers, vitamins, mineral supplements (e.g., iron, calcium, magnesium, and aluminum)
- Porphyria: acute intermittent
- Heavy metal poisoning: lead/arsenic poisoning
- Familial Mediterranean fever
- Paroxysmal nocturnal hemoglobinuria
- Irritable bowel syndrome
- Functional dyspepsia
- Centrally mediated abdominal pain syndrome (formerly functional abdominal pain syndrome)
- Narcotic bowel syndrome
- Abdominal migraine.
Classification by pathophysiology
- Intestinal, urinary, or biliary tract obstruction usually presents acutely. Partial or intermittent obstruction may take longer to recognize and lead to chronic or recurrent abdominal symptoms.
- Usually associated with an acute presentation. However, small perforations with spontaneous sealing and resulting in the formation of local abscesses may lead to chronic abdominal pain.
- Can lead to symptoms of chronic abdominal pain.
- Intestinal inflammation can involve different segments of the GI tract and be secondary to various etiologies. Common examples are esophageal inflammation due to gastroesophageal reflux, gastric inflammation due to Helicobacter pylori, and small and/or large bowel inflammation due to ulcerative colitis or Crohn disease.
- Inflammatory processes involving other GI organs (e.g., pancreas, liver, gallbladder) and non-GI organs (e.g., urinary bladder and kidneys) should also be considered.
- Reduction in intestinal blood flow (intestinal/mesenteric ischemia) may be acute in onset with serious and, sometimes, catastrophic consequences, or it may be chronic, leading to chronic or recurrent GI symptoms. Most patients with chronic mesenteric ischemia are asymptomatic due to good collateral circulation between the 3 mesenteric arteries. Symptoms arise when there is a significant occlusion of 2 of the 3 main mesenteric arteries.[22]
- Chronic mesenteric ischemia (sometimes also called intestinal angina) should be suspected mainly in older adult patients with underlying atherosclerotic vascular disease and/or a heavy smoking history who present with dull, crampy, upper/epigastric abdominal pain that usually appears within 1 hour after meals and subsides spontaneously over 2 to 3 hours. Other symptoms include nausea and vomiting, weight loss, and food aversion.
- Microvascular occlusive disease in patients with sickle cell disease, small-vessel vasculitis, low-flow state, or veno-occlusive disease.
- Calcification of mesenteric vessels on radiography is suggestive, but further testing with computed tomography or magnetic resonance imaging angiography is usually needed to confirm the diagnosis.[23]
- Various drugs cause inflammation, injury, or even ulceration of the intestinal mucosa.
- Examples include esophageal inflammation due to erythromycin or bisphosphonates, and gastric or small intestine inflammation due to chronic use of aspirin or NSAIDs.
- Certain drugs can cause abdominal symptoms, including pain, without overt inflammatory manifestations. Non-dihydropyridine calcium-channel blockers, such as diltiazem and verapamil, slow gut motility and lead to chronic constipation and pain. Common vitamin and mineral supplements, such as iron and calcium, can exacerbate constipation and abdominal pain, while magnesium and aluminum, in high doses, can cause loose stools, occasionally with crampy pain.
- Chronic narcotic use, in addition to contributing to chronic constipation, can contribute to visceral hyperalgesia or an oversensitive bowel. Prolonged use of narcotics, especially short-acting agents, causes a "soar and crash" effect where temporary pain relief leads to a more sensitive intestinal tract and thus greater pain and escalating narcotic use. Chronic abdominal pain that occurs in the setting of chronic narcotic use, with or without escalating doses, and providing no relief of the pain, is known as narcotic bowel syndrome (opioid-induced gastrointestinal hyperalgesia).[24] Symptoms of narcotic bowel syndrome may improve upon withdrawal of the opioid.[25]
- Centrally mediated abdominal pain syndrome (CAPS) is a functional GI disorder. It refers to conditions resulting from central nervous system sensitization with disinhibition of pain signals, rather than increased peripheral afferent excitability. Unlike irritable bowel syndrome and functional dyspepsia, pain associated with CAPS is reported to be constant and unrelated to peripheral events such as food intake or defecation.[25]
- Narcotic bowel syndrome (opioid-induced GI hyperalgesia) symptoms may improve upon withdrawal of the opioid.[25]
Differential Diagnosis
Diagnostic Approach
- History
- Physical exam
- Psychosocial assessment
- Investigations.
Symptoms assessment
- Epigastric and upper abdominal pain can indicate esophageal (e.g., gastroesophageal reflux), stomach (e.g., gastritis, gastroparesis), duodenal (e.g., ulcer), gallbladder (e.g., cholecystitis), or pancreatic (e.g., pancreatitis) origin.
- Lower abdominal pain can indicate large bowel involvement, and lateralization may help distinguish between descending/sigmoid colon (e.g., left-sided diverticulitis) and ascending/cecum (e.g., Crohn ileocolitis), or appendix (e.g., appendicitis).
- Pelvic pain can suggest gynecologic origin (e.g., ovarian cysts, pelvic inflammatory disease [PID]) or chronic pelvic pain syndrome (e.g., interstitial cystitis, endometriosis, urethral syndrome, or changes and dysfunction of the pelvic muscles).
- Pain made worse by eating (postprandial pain) may indicate gastric ulcer, chronic pancreatitis, gallstones, abdominal ischemia (also called abdominal angina), or functional disorders such as irritable bowel syndrome, gastroparesis, functional dyspepsia, or postprandial distress syndrome (postprandial fullness).
- Pain relieved by eating suggests duodenal peptic ulcer disease.
- Pain relieved by defecation may indicate irritable bowel syndrome.[31]
- Pain associated with menstrual cycle suggests gynecologic origin. Additional symptoms of dyspareunia, dysmenorrhea, pain with defecation, and infertility suggest endometriosis.[32]
- Pain associated with urinary urgency and frequent urination suggests interstitial cystitis.[33]
Physical exam
- Temporal muscle wasting, sunken eyes, and prominent clavicles, suggesting significant weight loss
- Dry mucosal membranes, indicating volume depletion
- Icteric sclera, indicating hepatobiliary disease
- Pale conjunctiva, suggesting anemia.
Psychosocial assessment
Investigations
- CBC with differential, to screen for infection or anemia.[35] The platelet count and erythrocyte sedimentation rate may signify an inflammatory process.
- Serum electrolytes, glucose, creatinine, and BUN for metabolic causes.
- Liver function tests, lipase, and amylase, particularly in patients with upper abdominal pain.
- Urine analysis and urine culture to help exclude urinary tract infection and interstitial cystitis.[33]
- Stool tests for culture, ova and parasites, and Giardia antigen should be done if bacterial, parasitic, or protozoal cause of abdominal pain is suspected.
- Urine or serum pregnancy test: this should also be done prior to radiographic or endoscopic investigations.
- Serology testing for Helicobacter pylori in patients with upper gastrointestinal symptoms, including early satiety and epigastric discomfort (i.e., dyspeptic symptoms).
- Serology testing including immunoglobulin A tissue transglutaminase (IgA-tTG), immunoglobulin G tissue transglutaminase (IgG-tTG), IgG-deamidated gliadin peptides (DGPs), and endomysial antibody (EMA) for patients with suspected celiac disease.[43]
- Vaginal swabs, prostate-specific antigen, and urine cytology can be helpful in certain cases with pelvic and lower abdominal pain.
- Assessment for colorectal cancer: US and UK guidelines report risk thresholds for testing symptomatic patients.[44] [45] [46] US guidelines recommend adults ages <50 years with colorectal bleeding symptoms undergo colonoscopy or evaluation sufficient to determine a bleeding cause.[44] UK guidelines recommend certain quantitative fecal immunochemical tests (FITs) to guide referral for suspected colorectal cancer in adults:[45] [46]
- ages 40 years and over with unexplained weight loss and abdominal pain
- ages under 50 years with rectal bleeding and unexplained abdominal pain
- ages 50 years and over with unexplained abdominal pain.
- Upper endoscopy is indicated if the pain is localized in the upper abdomen, particularly if other upper GI symptoms (early satiety, nausea, vomiting) are present or if celiac disease is highly suspected.[43]
- The UK National Institute for Health and Care Excellence (NICE) recommends that patients ages 55 years and over with upper abdominal pain and weight loss should have urgent upper endoscopy (within 2 weeks).[45] Those ages 55 years and over with upper abdominal pain with a raised platelet count or low hemoglobin levels or nausea and vomiting should have nonurgent upper endoscopy.[45]
- Pelvic abdominal ultrasound and transvaginal and/or transrectal ultrasound is indicated for evaluating lower abdominal pain.[49]
- CT scanning and/or MRI can help evaluate dilated intestinal loops; exclude partial intestinal obstruction; detect abnormalities in other abdominal organs (e.g., pancreas, liver, kidneys); identify inflammatory processes (e.g., inflammatory bowel disease, diverticulitis, abscesses); investigate retroperitoneal or pelvic masses; and identify congenital anatomic abnormalities (e.g., duodenal duplication cyst).[50] [51]
- Abdominal ultrasound can be used to determine the presence of postsurgical adhesions between bowel and the abdominal wall.[52] MRI can be used to visualize adhesions between viscera; however, there is a tendency to over diagnose adhesions.[52] There is insufficient evidence to support the use of CT as a diagnostic modality for adhesions.[52] Gastric emptying study should be considered in patients with symptoms suggesting gastroparesis.[53]
- Abdominal laparoscopy may be considered in appropriate patients with chronic abdominal pain, in whom organic etiology is suspected. Diagnostic laparoscopy may be used to identify organic causes such as intestinal adhesions, internal hernias, enlarged mesenteric lymph nodes, endometriosis, and chronic appendicitis.[54]
Functional GI disorders
Citations
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