One-liner#

Evaluate chronic abdominal pain (>4 weeks) to distinguish functional disorders (IBS, functional dyspepsia) from organic pathology, using alarm features to guide workup intensity while avoiding excessive testing in low-risk patients.

Quick nav#

Red flags / send to ED#

Chronic abdominal pain rarely requires ED referral, but send if:

  • Acute severe exacerbation with peritoneal signs
  • GI bleeding with hemodynamic instability
  • Bowel obstruction (vomiting, distension, obstipation)
  • Signs of perforation (rigid abdomen, free air)

Alarm features (warrant expedited workup, not necessarily ED)#

  • Unintentional weight loss (>5% in 6 months)
  • GI bleeding (melena, hematochezia, positive FOBT)
  • Iron deficiency anemia
  • Progressive dysphagia
  • Persistent vomiting
  • Palpable abdominal mass
  • Family history of GI malignancy (especially colorectal, gastric, pancreatic)
  • Age >50 with new-onset symptoms
  • Nocturnal symptoms waking patient from sleep
  • Fever of unknown origin

Key history#

Pain characteristics:

  • Location: epigastric (dyspepsia, PUD, chronic pancreatitis), periumbilical (IBS, functional), RUQ (biliary, hepatic), LLQ (diverticular disease, IBS-C)
  • Quality: crampy/colicky (IBS, partial obstruction), burning (dyspepsia), constant dull ache (chronic pancreatitis, malignancy)
  • Timing: relation to meals (worse with eating: mesenteric ischemia, gastroparesis; better with eating: PUD), relation to bowel movements (IBS improves with defecation)
  • Duration and pattern: episodic vs constant; progressive vs stable

Associated symptoms:

  • Bowel habits: diarrhea, constipation, alternating (IBS subtypes)
  • Bloating and distension: common in IBS, SIBO, gastroparesis
  • Nausea/vomiting: gastroparesis, obstruction, functional
  • Dyspepsia: early satiety, postprandial fullness
  • Extraintestinal: joint pain (IBD), skin changes (celiac, IBD), fatigue

Rome IV criteria for IBS (recurrent abdominal pain ≥1 day/week in last 3 months, with onset ≥6 months ago, associated with ≥2 of):

  • Related to defecation
  • Change in stool frequency
  • Change in stool form/appearance

IBS subtypes (based on Bristol Stool Scale on days with abnormal stools):

  • IBS-D: >25% loose/watery (Bristol 6–7), <25% hard (Bristol 1–2)
  • IBS-C: >25% hard (Bristol 1–2), <25% loose (Bristol 6–7)
  • IBS-M (mixed): >25% both hard and loose
  • IBS-U (unclassified): doesn’t meet criteria for other subtypes

Dietary and lifestyle:

  • Dietary triggers: lactose, fructose, gluten, FODMAPs, fatty foods
  • Alcohol and caffeine intake
  • Fiber intake
  • Stress and psychological factors (strong association with functional disorders)

Medication review:

  • NSAIDs (gastropathy, ulcers)
  • Opioids (constipation, narcotic bowel syndrome)
  • Metformin (GI side effects)
  • Antibiotics (C. diff, dysbiosis)
  • PPIs (SIBO risk with long-term use)
  • Supplements (iron causes constipation; magnesium causes diarrhea)

Past medical/surgical history:

  • Prior abdominal surgeries (adhesions, short bowel, bile acid malabsorption post-cholecystectomy)
  • Diabetes (gastroparesis)
  • Autoimmune diseases (celiac, IBD)
  • Psychiatric history (anxiety, depression strongly associated with functional GI disorders)

Focused exam#

  • Vitals: usually normal in chronic pain; weight trend important
  • General: nutritional status, signs of chronic illness
  • Abdominal: tenderness location, masses, organomegaly, distension, surgical scars
  • Carnett’s sign: tenderness that increases with abdominal wall tension (suggests abdominal wall pain, not visceral)
  • Rectal exam: if bleeding, constipation, or mass suspected
  • Skin: jaundice (biliary/hepatic), dermatitis herpetiformis (celiac), erythema nodosum/pyoderma gangrenosum (IBD)
  • Lymph nodes: if malignancy concern

Differential (quick pattern recognition)#

Common/likely (outpatient)#

DiagnosisKeywords patients useKey cluesFocused exam cluesInitial next step
IBS“Crampy,” “bloated,” “comes and goes,” “better after I go”Rome IV criteria; no alarm features; symptoms for months/years; stress-relatedMild diffuse tenderness; no masses; normal labsPositive diagnosis (Rome IV); limited workup; dietary modification + symptomatic treatment
Functional dyspepsia“Burning,” “full after a few bites,” “uncomfortable after eating”Postprandial distress or epigastric pain; no alarm features; normal EGDEpigastric tenderness; no massesH. pylori test-and-treat; PPI trial; consider EGD if no response
Chronic constipation“Bloated,” “straining,” “don’t go for days”Infrequent BMs; hard stools; straining; incomplete evacuationLLQ fullness; palpable stoolFiber, fluids, osmotic laxatives; colonoscopy if alarm features
GERD“Heartburn,” “acid,” “worse lying down”Postprandial; supine worsening; responds to antacidsEpigastric tendernessPPI trial; EGD if alarm features or refractory
Lactose intolerance“Bloated after milk,” “gas,” “diarrhea after dairy”Symptoms with dairy; ethnic predisposition; resolves with avoidanceNormal examTrial of lactose elimination; lactase supplements
Bile acid diarrhea“Diarrhea since gallbladder surgery,” “urgent,” “watery”Post-cholecystectomy; watery diarrhea; urgencyNormal examTrial of cholestyramine; SeHCAT if available
Chronic mesenteric ischemia“Pain after eating,” “afraid to eat,” “lost weight”Postprandial pain (intestinal angina); weight loss; vascular diseaseAbdominal bruit; signs of PVDCTA or MRA; vascular surgery referral
Abdominal wall pain“Sore spot,” “worse with movement,” “tender to touch”Localized; worse with Valsalva; positive Carnett’s signPoint tenderness; positive Carnett’sReassurance; trigger point injection if refractory

Can’t-miss / urgent#

DiagnosisKeywords patients useKey cluesFocused exam cluesInitial next step
Colorectal cancer“Blood in stool,” “thinner stools,” “lost weight”Age >50; alarm features; family history; iron deficiency anemiaMass on rectal exam; occult blood positiveColonoscopy urgently
IBD (Crohn’s, UC)“Bloody diarrhea,” “cramping,” “joint pain,” “mouth sores”Young onset; bloody diarrhea; extraintestinal manifestations; family historyPerianal disease (Crohn’s); abdominal tendernessCBC, CRP, fecal calprotectin; GI referral for colonoscopy
Celiac disease“Bloated,” “diarrhea,” “tired all the time”Diarrhea, bloating, fatigue; iron/B12 deficiency; family history; associated autoimmune diseasesMay be normal; dermatitis herpetiformisTTG-IgA + total IgA; EGD with duodenal biopsies if positive
Chronic pancreatitis“Deep pain,” “goes to my back,” “worse after eating”Alcohol history; recurrent pancreatitis; steatorrhea; diabetesEpigastric tenderness; weight lossLipase (may be normal); CT or MRCP; fecal elastase
Pancreatic cancer“Deep ache,” “back pain,” “lost appetite,” “jaundice”Age >50; new diabetes; weight loss; painless jaundiceJaundice; palpable gallbladder (Courvoisier’s); cachexiaCT abdomen; CA 19-9; urgent GI/oncology referral
Ovarian cancer“Bloated,” “pelvic pressure,” “feeling full quickly”Postmenopausal; persistent bloating; early satiety; pelvic symptomsPelvic/adnexal massPelvic ultrasound; CA-125; GYN oncology referral

Workup#

Initial workup (all patients with chronic abdominal pain):

  • CBC: anemia (bleeding, malabsorption, chronic disease)
  • CMP: electrolytes, renal/liver function
  • Consider: CRP or ESR (inflammation), TSH (thyroid dysfunction causing GI symptoms)

If IBS suspected (Rome IV criteria, no alarm features):

  • Limited workup is appropriate—avoid excessive testing
  • Consider: CBC, CRP, celiac serology (TTG-IgA), fecal calprotectin (to rule out IBD)
  • Colonoscopy NOT routinely needed if <45 without alarm features

If alarm features present:

  • Colonoscopy: age >45, rectal bleeding, iron deficiency anemia, weight loss, family history CRC
  • EGD: dysphagia, persistent vomiting, epigastric mass, anemia with upper GI symptoms
  • CT abdomen/pelvis: mass, unexplained weight loss, suspected malignancy
  • Celiac serology: diarrhea, bloating, iron/B12 deficiency, family history

Specialized testing:

  • Fecal calprotectin: elevated in IBD, helps distinguish from IBS (>150 μg/g suggests organic disease)
  • Fecal elastase: <200 μg/g suggests pancreatic insufficiency
  • Hydrogen breath testing: SIBO, lactose/fructose intolerance
  • Gastric emptying study: suspected gastroparesis
  • MRCP: biliary/pancreatic pathology

When NOT to order extensive workup:

  • Classic IBS meeting Rome IV criteria without alarm features in patient <45
  • Symptoms clearly related to dietary triggers that resolve with elimination
  • Stable, long-standing symptoms without change in pattern
  • Abdominal wall pain with positive Carnett’s sign

Initial management#

  • Alarm features present: Expedited workup (colonoscopy, imaging) before empiric treatment
  • No alarm features, IBS pattern: Positive diagnosis; reassurance; dietary modification; symptomatic treatment
  • Dyspepsia pattern: H. pylori test-and-treat; PPI trial
  • Address contributing factors: Stress, anxiety, depression; dietary triggers; medication side effects

Management by diagnosis#

Irritable bowel syndrome (IBS)#

Education:

  • IBS is a real condition involving gut-brain interaction—not “all in your head”
  • Symptoms wax and wane; goal is management, not cure
  • Dietary changes, stress management, and medications all help
  • IBS does not increase risk of cancer or IBD

Treatment:

Dietary modifications (first-line):

  • Low-FODMAP diet: effective in 50–80%; work with dietitian for proper elimination and reintroduction
  • Identify and avoid individual triggers (dairy, gluten, caffeine, alcohol)
  • Adequate fiber (gradually increase to avoid worsening bloating)

IBS-D (diarrhea-predominant):

DrugDoseContraindicationsMonitoringCostNotes
Loperamide2 mg PRN or scheduled (max 16 mg/day)Bloody diarrhea; C. diffNone$First-line for diarrhea; use PRN or before triggers
Rifaximin550 mg TID x 14 daysNone significantNone$$$$FDA-approved for IBS-D; can repeat if recurrence; expensive
Eluxadoline100 mg BID (75 mg if no gallbladder)No gallbladder (75 mg ok); pancreatitis; alcohol use; biliary obstructionLFTs$$$$Mixed opioid agonist/antagonist; avoid if heavy alcohol use
Alosetron0.5–1 mg BIDConstipation; ischemic colitis historyConstipation; ischemic symptoms$$$$Women with severe IBS-D only; restricted prescribing program
Dicyclomine10–20 mg QID PRNGlaucoma; urinary retention; elderlyAnticholinergic effects$Antispasmodic; use PRN for cramping

IBS-C (constipation-predominant):

DrugDoseContraindicationsMonitoringCostNotes
Psyllium (Metamucil)1 tsp daily, titrate upBowel obstructionBloating initially$Soluble fiber; increase gradually
Polyethylene glycol (MiraLAX)17 g dailyBowel obstructionNone$Osmotic laxative; adjust dose to effect
Linaclotide290 μg daily (145 μg for chronic constipation)Bowel obstruction; pediatricDiarrhea$$$Take 30 min before breakfast; effective for pain + constipation
Plecanatide3 mg dailyBowel obstruction; pediatricDiarrhea$$$Similar to linaclotide; may have less diarrhea
Lubiprostone8 μg BIDBowel obstructionNausea$$$Chloride channel activator; take with food to reduce nausea

For pain/global symptoms:

DrugDoseContraindicationsMonitoringCostNotes
Amitriptyline10–25 mg QHS; titrate to 50–75 mgGlaucoma; urinary retention; cardiac disease; elderlyECG if cardiac risk; anticholinergic effects$Low-dose TCA; helps pain and diarrhea; sedating
Nortriptyline10–25 mg QHS; titrate to 50–75 mgSame as amitriptylineSame$Less sedating than amitriptyline
Duloxetine30 mg daily; titrate to 60 mgMAOIs; uncontrolled glaucoma; hepatic impairmentBP; hepatic function$$SNRI; helps pain; also treats comorbid anxiety/depression
Peppermint oil (IBgard)180 mg TID before mealsGERD (can worsen)None$$Antispasmodic; enteric-coated to avoid heartburn

Follow-up: 4–6 weeks after initiating treatment; adjust based on response. Consider GI referral if refractory.

Functional dyspepsia#

Education:

  • Stomach discomfort without ulcer or other structural cause
  • Related to how the stomach processes food and signals to the brain
  • Often improves with treatment but may recur

Treatment:

  • H. pylori test-and-treat (if not previously done)
  • PPI trial x 4–8 weeks
  • If PPI fails: prokinetic or TCA
DrugDoseContraindicationsMonitoringCostNotes
Omeprazole20 mg daily x 4–8 weeksNone absoluteMg if prolonged$First-line; 30 min before breakfast
Amitriptyline10–25 mg QHSCardiac disease; glaucoma; elderlyECG if risk factors$If PPI fails; helps visceral hypersensitivity
Metoclopramide5–10 mg TID before meals (max 12 weeks)Parkinson’s; tardive dyskinesia; bowel obstructionTardive dyskinesia (limit duration)$Prokinetic; avoid long-term use
Buspirone10 mg TIDNone significantNone$Fundic relaxation; helps early satiety

Follow-up: 4–8 weeks; EGD if no response to empiric therapy or alarm features develop.

Celiac disease#

Education:

  • Autoimmune reaction to gluten (wheat, barley, rye)
  • Lifelong strict gluten-free diet is the only treatment
  • Even small amounts of gluten cause intestinal damage
  • Associated with other autoimmune conditions; family members should be screened

Treatment:

  • Strict gluten-free diet (GFD)—refer to dietitian experienced in celiac
  • Screen for and treat nutritional deficiencies (iron, B12, folate, vitamin D, calcium)
  • Bone density screening (increased osteoporosis risk)
  • Pneumococcal vaccination (functional hyposplenism)
SupplementDoseNotes
IronPer deficiency severityCommon at diagnosis; recheck after GFD
Vitamin D1000–2000 IU dailyMaintain 25-OH vitamin D >30
Calcium1000–1200 mg dailyIf dietary intake inadequate
B12Per deficiencyLess common than iron deficiency

Follow-up: TTG-IgA at 6 and 12 months to confirm adherence; should normalize. GI follow-up for repeat biopsy if symptoms persist despite GFD.

Chronic pancreatitis#

Education:

  • Irreversible damage to pancreas, often from alcohol
  • Abstinence from alcohol is essential to slow progression
  • May need enzyme supplements to digest food
  • Increased risk of diabetes and pancreatic cancer

Treatment:

  • Alcohol cessation (most important intervention)
  • Pain management (challenging; avoid opioids if possible)
  • Pancreatic enzyme replacement if steatorrhea or malnutrition
DrugDoseContraindicationsMonitoringCostNotes
Pancrelipase (Creon, Zenpep)40,000–50,000 lipase units with meals; 20,000–25,000 with snacksNoneWeight, stool frequency, nutritional status$$$$Titrate to control steatorrhea; take with first bite of food
Acetaminophen650–1000 mg Q6H (max 3g/day)Liver diseaseLFTs$First-line for pain
Pregabalin75 mg BID; titrate to 150–300 mg BIDRenal impairment (adjust dose)Sedation; edema$$Adjunct for neuropathic pain component

Follow-up: GI co-management; monitor for diabetes (fasting glucose, A1c); nutritional status; pain control. Consider referral to pain specialist if refractory.

Abdominal wall pain#

Education:

  • Pain from muscles, nerves, or fascia of the abdominal wall—not from internal organs
  • Often mistaken for visceral pain, leading to unnecessary testing
  • Usually responds well to local treatment

Treatment:

  • Reassurance and explanation
  • NSAIDs or topical analgesics
  • Trigger point injection if localized and refractory
DrugDoseContraindicationsMonitoringCostNotes
Ibuprofen400–600 mg TIDGI bleed; CKD; CV diseaseCr if prolonged$First-line
Topical lidocaine 4% patchApply to affected area 12 hours on/12 hours offNoneSkin irritation$$Good for localized pain
Trigger point injection1–2 mL lidocaine 1% or bupivacaine 0.25%Infection at site; anticoagulationNone$ (procedure)Often diagnostic and therapeutic

Follow-up: 2–4 weeks; if not improving, reconsider diagnosis.

Follow-up#

  • IBS: 4–6 weeks after starting treatment; ongoing as needed for flares
  • Functional dyspepsia: 4–8 weeks after PPI trial; EGD if no response
  • Celiac: 6 and 12 months for TTG-IgA; annual thereafter
  • Chronic pancreatitis: GI co-management; every 3–6 months

When to refer to GI:

  • Alarm features requiring endoscopy
  • Suspected IBD
  • Refractory IBS despite first-line treatments
  • Abnormal celiac serology
  • Chronic pancreatitis
  • Diagnostic uncertainty after initial workup

Patient instructions#

  • Keep a food and symptom diary to identify triggers.
  • Eat smaller, more frequent meals rather than large meals.
  • Manage stress—it can worsen digestive symptoms. Consider relaxation techniques or counseling.
  • Take medications as prescribed, even if you feel better.
  • Avoid NSAIDs (ibuprofen, naproxen) unless your doctor says it’s okay—they can irritate the stomach.
  • Call the office if you notice blood in your stool, unintentional weight loss, or worsening symptoms.
  • Follow up as scheduled to monitor your progress.

Smartphrase snippets#

.IBSDX Chronic abdominal pain meeting Rome IV criteria for IBS. No alarm features (no weight loss, GI bleeding, anemia, or family history of GI malignancy). Limited workup appropriate. Plan: dietary modification (low-FODMAP trial), fiber supplementation, and symptomatic treatment. Discussed chronic nature of IBS and management goals.

.CHRONABDPAINWORKUP Chronic abdominal pain with [alarm feature]. Ordered [CBC, CMP, celiac serology, fecal calprotectin, colonoscopy/EGD/CT]. Will reassess after results. Discussed importance of completing workup given concerning features.

.FUNCTIONALGI Chronic abdominal symptoms consistent with functional GI disorder. Extensive prior workup negative including [list]. Symptoms do not suggest organic pathology. Plan: focus on symptom management with [dietary changes/neuromodulator/antispasmodic]. Discussed gut-brain connection and realistic expectations for management.

Backward Abdominal Pain (Acute) Nausea/Vomiting Forward