Gastric and Small Bowel Motility

• Audio chapter
  Single-voice audio, listen on the commute.
• ABIM-format MCQs
  5-option vignettes with full wrong-answer teaching.
• Study guide
  Tables, decision trees, primary sources.
• AI tutor
  Chapter-grounded, answers the question you're stuck on.

What this chapter covers

• Section 8.1: Gastric motor physiology and gastroparesis pathogenesis

  Gastric emptying is a coordinated act between three systems, and gastroparesis is what happens when any one of them fails.

• Section 8.2: Gastroparesis diagnosis

  Gastroparesis cannot be diagnosed on symptoms alone because the symptoms (nausea, vomiting, early satiety, postprandial fullness, bloating, upper abdominal pain) overlap with functional dyspepsia, peptic ulcer disease, gastric outlet obstruction, cyclic vomiting syndrome, rumination, eating disorders, and chronic cannabinoid use.

• Section 8.3: Gastroparesis treatment

  Gastroparesis treatment is a stepladder, and the first rungs are the most powerful.

• Section 8.4: Cyclic vomiting syndrome and CHS

  Cyclic vomiting syndrome and cannabinoid hyperemesis syndrome share a striking clinical pattern of stereotyped vomiting episodes separated by symptom-free intervals, but they diverge on cause, on family history, and on treatment, and the two are distinguished by a small number of high-yield clues.

• Section 8.5: Small bowel motility and pseudo-obstruction

  Pseudo-obstruction is the syndrome of impaired propulsive motility that mimics mechanical obstruction without an occluding lesion.

• Section 8.6: Functional dyspepsia

  Functional dyspepsia is the most common upper GI complaint in primary care and gastroenterology clinics, with a worldwide prevalence of 5 to 11 percent and up to 40 percent of affected patients seeking medical care.

Podcast episodes

1. 01

   Gastroparesis

   Gastroparesis is one phenotype with three failure points: the vagus for accommodation and coordination, the interstitial cells of Cajal for rhythm, and smooth muscle for force. Diabetes hits two of the three, surgery hits the vagus, idiopathic disease hits the pacemaker, and drugs mimic the whole picture by slowing the antrum. Four-hour scintigraphy with strict drug holds and controlled glucose anchors the diagnosis, and the favored move is often to stop a drug rather than confirm a disease.

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2. 02

   CVS Pseudo FD

   Episode two of the Gastric and Small Bowel Motility chapter covers the episodic and functional presentations where the structural workup comes back clean and the pattern carries the diagnosis: cyclic vomiting syndrome, cannabinoid hyperemesis, chronic intestinal pseudo-obstruction, and functional dyspepsia. Reading dilated bowel or delayed emptying as mechanical disease misleads you every time. Each condition is answered by naming the pattern, not by another motility drug.

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Key topics

• ·Three-system model of gastric emptying
• ·Diabetic and idiopathic gastroparesis
• ·GLP-1 agonists and drug-induced delay
• ·Four-hour gastric emptying scintigraphy
• ·Pre-test drug holds and glucose control
• ·Prokinetic drugs by mechanism
• ·Antiemetics and refractory interventions
• ·Emptying-symptom mismatch
• ·Cyclic vomiting syndrome and migraine biology
• ·Cannabinoid hyperemesis and hot-water bathing
• ·Rumination and chronic nausea/vomiting syndrome
• ·Acute colonic pseudo-obstruction (Ogilvie)
• ·Chronic intestinal pseudo-obstruction
• ·Neuropathic vs myopathic manometry
• ·Paraneoplastic pseudo-obstruction (anti-Hu, SCLC)
• ·Functional dyspepsia subtypes and alarm features