Gastric and Small Bowel Motility: Gastric and Small Bowel Motility: Three Syndromes

0:00Welcome to Board Pearls. This is episode two of two of the Gastric and Small Bowel Motility chapter, in the Stomach and Small Bowel Disorders module. This episode covers three problems after gastroparesis. A young woman with attacks of vomiting has cyclic vomiting syndrome, and a young man with the same attacks has the cannabis syndrome that copies it. A woman with scleroderma has a bowel that behaves as if it's blocked when nothing blocks it, chronic intestinal pseudo-obstruction, and an older smoker shows the cause that mustn't be missed. And a woman with early fullness and a man with epigastric burning have functional dyspepsia, its two subtypes. For each patient, the case shows the diagnosis and its definition, the question or test that rules out the alternatives, and how the mechanism chooses the treatment. The acute colonic form of pseudo-obstruction, Ogilvie syndrome, is a hospital emergency with its own decompression steps, and it isn't the subject here.

0:57Here's the first patient. A nineteen-year-old woman has had six attacks of vomiting over the past year. Each one starts in the early morning with sweating, pallor, and a sense of doom. Then she vomits up to a dozen times an hour for about two days and ends up in the emergency department for fluids. Then she's completely well for one to three months until the next attack. Her attacks often come during exam weeks or after nights without sleep. She has migraines, and so does her mother. Her endoscopy and labs between attacks are normal.

1:28Her pattern points to cyclic vomiting syndrome, and in this disease the pattern largely is the diagnosis. Cyclic vomiting syndrome is stereotyped attacks of severe nausea and vomiting lasting hours to days, separated by symptom-free intervals of weeks to months. Each attack resembles the others in how it starts, how long it lasts, and how bad it gets. The criteria require at least two attacks in six months, or three in a year. She's had six nearly identical attacks with well months between them.

1:59Each attack runs through four phases, and the phases are what separate it from continuous nausea. The interval between attacks is symptom-free. The prodrome brings nausea, sweating, pallor, and the feeling that vomiting is coming, and her early-morning sweating and sense of doom are exactly that. The vomiting phase is intense and self-limited, with retching, sometimes abdominal pain, and dehydration. Recovery takes hours, with a full return to normal. A patient who feels sick most days doesn't have cyclic vomiting, however bad her worst days are.

2:31Before the label is final, each alternative is ruled out with a specific question or test. Gastroparesis causes continuous symptoms, and between attacks of cyclic vomiting, gastric emptying is normal or even fast. Chronic nausea and vomiting syndrome is bothersome nausea or vomiting at least one day a week without the episodic pattern, and her weeks of wellness exclude it. Rumination is effortless regurgitation of recognizable food within minutes of eating, without retching, and her retching excludes it.

3:02Two more alternatives need questions asked directly. Eating disorders, bulimia and atypical anorexia, belong on the list when vomiting comes with weight changes, so she's asked about eating, weight, and body image, gently and directly, and she has no weight change and no concerns. And the most important question is whether she uses cannabis, because daily cannabis produces a syndrome that copies cyclic vomiting almost exactly and is treated completely differently. She's also asked whether hot showers help during an attack. She doesn't use cannabis, and hot showers make no difference. She has cyclic vomiting syndrome.

3:39Her family history explains the treatment. The biology of cyclic vomiting resembles migraine. Many patients have migraines themselves or in the family, and the same triggers bring on both: stress, lack of sleep, certain foods, and menstruation. Anxiety and depression are common companions. Her own migraines, her mother's, and attacks set off by exams and lost sleep are the migraine pattern, and the drugs that prevent her attacks are borrowed from migraine prevention.

4:09With attacks this frequent, she needs prevention. The preferred drug is a tricyclic, amitriptyline or nortriptyline, at bedtime, titrated from twenty-five up to one hundred milligrams, and in case series about seventy to eighty percent respond. Topiramate is next, and propranolol, mirtazapine, gabapentin, and zonisamide are others. Lifestyle is the foundation, with regular sleep, especially during exams, stress management, and avoiding identified triggers, because these are the same triggers that start her attacks.

4:40She also needs a plan to stop an attack once it starts. It includes intravenous fluids for dehydration; an antiemetic such as ondansetron; a benzodiazepine like lorazepam, which helps both the nausea and the panic-like distress; and subcutaneous sumatriptan when the attack behaves like a migraine. Aprepitant, a neurokinin-one antagonist, has been used for severe attacks that don't respond.

5:04She starts amitriptyline at bedtime, titrated over several weeks, with a written attack plan: sumatriptan and ondansetron at home, and the emergency department for fluids if she can't keep anything down. She works on her sleep during exam weeks. Over the next six months, she has one mild attack and manages it at home.

5:22The second patient's attacks look the same, but his history answers the two questions differently. A twenty-seven-year-old man has the same kind of attacks, days of relentless vomiting, then weeks of feeling well, with five emergency visits. He has no migraines and no family history of them. When asked about cannabis, he says he's smoked it daily for six years. When asked what helps, he says the only thing that works during an attack is standing in a hot shower, sometimes for hours, several times a day.

5:53That's cannabinoid hyperemesis syndrome. It mirrors cyclic vomiting in its pattern, but it follows years of regular cannabis use, and compulsive hot bathing that brings dramatic relief is its hallmark. He mentioned neither the cannabis nor the showers until asked directly, which is why both questions belong in every history of episodic vomiting.

6:13Its mechanism explains the showers. It involves the transient receptor potential vanilloid one, TRPV1, receptor, which responds to heat and capsaicin. Chronic tetrahydrocannabinol, THC, desensitizes cannabinoid receptors and disrupts TRPV1 signaling in the brainstem and gut. Heat activates TRPV1, which is why hot water helps, and capsaicin cream on the skin, another TRPV1 activator, gives partial relief.

6:39Stopping cannabis is curative, and attacks usually stop within one to two weeks of abstinence. Stopping is hard, so he usually needs addiction and behavioral support, not just advice. Tricyclics and ondansetron aren't effective in cannabis hyperemesis. A young adult with daily cannabis use, stereotyped attacks, and relief from hot showers needs to stop cannabis, not start nortriptyline.

7:02The two syndromes separate on four points. Cyclic vomiting tends to begin in childhood or adolescence, comes with personal or family migraine, has no hot-shower behavior, and responds to tricyclic prevention. Cannabis hyperemesis begins in adulthood after years of regular use, comes with compulsive hot bathing, and responds only to stopping cannabis.

7:23The third patient has symptoms of obstruction with nothing blocking her bowel. A forty-eight-year-old woman with systemic sclerosis, diagnosed six years ago, has had a year of abdominal distension, bloating, vomiting after meals, and diarrhea, with twenty pounds of weight loss. She's been admitted three times with what looked like small bowel obstruction. Each time, computed tomography, CT, showed dilated small bowel loops with no transition point, and each time it settled without surgery. Her duodenum is markedly dilated on imaging.

7:55She has chronic intestinal pseudo-obstruction, severe, long-standing failure of the bowel's propulsive motility. It causes recurring or continuous symptoms of obstruction, distension, vomiting, inability to pass stool, and weight loss, with no blocking lesion on imaging, endoscopy, or surgery. Dilated loops with no transition point mean there's no single place where the bowel narrows, and episodes that resolve without surgery fit a bowel that fails to push, not one that's blocked.

8:25Its epidemiology shapes her workup. It's rare, with a prevalence in the low single digits per hundred thousand, and about half of adult cases are caused by another disease. So the workup looks for the cause as well as the motility problem.

8:40Her workup starts by proving there's truly no mechanical obstruction, because missing a real obstruction is the worst mistake. CT or magnetic resonance, MR, enterography, a barium small bowel study, and endoscopy as needed look for a stricture, adhesions, or a mass. Hers show none.

9:01The dysmotility and its extent are proven next, because any level can be affected. Gastric emptying scintigraphy assesses the stomach. A wireless motility capsule or whole-gut scintigraphy assesses small bowel transit. Esophageal manometry checks the esophagus, which matters especially in scleroderma, where the esophagus often loses its contractions. Hers show slow gastric emptying, slow small bowel transit, and absent esophageal contractions.

9:28Then the lesion is characterized, nerves or muscle, because the pattern guides the search for a cause. In neuropathic pseudo-obstruction, the enteric nerves are damaged and the muscle is normal, so contractions are strong but disorganized. In myopathic pseudo-obstruction, the smooth muscle fails, so contractions are organized but weak. In a third form, the interstitial cells of Cajal are lost, so the pacemaker fails. Many secondary causes are mixed or shift over time.

9:59Antroduodenal manometry, available only at specialized centers, is the most specific test for telling them apart. A catheter with sensors across the antrum, duodenum, and upper jejunum records pressure while fasting and after a meal. The fasting gut normally runs the migrating motor complex. Phase one is quiet, phase two brings irregular contractions, and phase three is a strong, propagated band of contractions that sweeps the bowel clean, repeating every ninety to one hundred twenty minutes. After a meal, that's replaced by hours of irregular, strong mixing contractions, lasting longer the more calories the meal holds.

10:33The two diseases distort that pattern in different ways. In neuropathic disease, contractions are normal in strength but disorganized: phase three is missing or doesn't propagate, there are clustered or burst contractions, and the fed pattern ends too early. In myopathic disease, the pattern is there, but every contraction is weak. Manometry can also reveal a mechanical obstruction that imaging missed, as clustered, prolonged contractions above the blockage.

11:01When everything else is inconclusive, a full-thickness biopsy at laparoscopy can show the nerve or muscle disease directly. Her manometry shows low-amplitude contractions throughout fasting and after the meal, with the motor complex still present. She has myopathic pseudo-obstruction.

11:17Half of adult cases have an underlying cause, so it's sought next, and connective tissue diseases lead. Scleroderma is the prototype. About eighty percent of scleroderma patients have measurable upper gut dysmotility, typically neuropathic at first and myopathic later, with progressive loss of contractile force. The imaging hallmark is megaduodenum, a markedly dilated second and third part of the duodenum, as she has. Lupus, dermatomyositis, and Ehlers-Danlos syndrome are other connective tissue causes.

11:49The other secondary causes span many systems. Amyloidosis, light chain or transthyretin, infiltrates the muscle, often with autonomic dysfunction in light-chain disease. Hypothyroidism, hyperparathyroidism, and diabetes cause mixed patterns. Parkinson disease, multiple sclerosis, myasthenia gravis, and autonomic neuropathy cause neuropathic patterns. Opioids, tricyclics, anticholinergics, and antiparkinsonian drugs cause or worsen it.

12:20Two rarer causes have recognizable patients. A young, cachectic patient with limited eye movements, white matter disease of the brain, a peripheral neuropathy, and severe gut dysmotility should raise mitochondrial neurogastrointestinal encephalomyopathy, MNGIE, a mitochondrial disorder from thymidine phosphorylase deficiency. The remaining cases are primary, or idiopathic, including familial visceral neuropathy and myopathy in some families.

12:51The screen for secondary causes follows that list. It's thyroid function; scleroderma antibodies, anti-Scl-70, anticentromere, and anti-RNA polymerase three; the paraneoplastic antibody panel with a chest CT; a rectal biopsy for amyloid when systemic features suggest it; and metabolic testing for mitochondrial disease when the picture fits. Her cause is clear, but her medications are still reviewed for opioids and anticholinergics.

13:24Her treatment is mainly supportive, and nutrition comes first. She eats by mouth while she can. When oral intake fails, jejunal feeding takes over, usually through a combined tube. Its jejunal port feeds beyond a stomach that doesn't empty, and its gastric port vents the trapped fluid and gas that cause distension and vomiting. Twenty to fifty percent of patients eventually need long-term home parenteral nutrition.

13:50Her diarrhea points to the complication that's almost always present. Small intestinal bacterial overgrowth is essentially universal in pseudo-obstruction, adding bloating, diarrhea, and malabsorption. It's treated with rotating antibiotic courses, typically two weeks a month, cycling rifaximin, metronidazole, ciprofloxacin, doxycycline, or amoxicillin-clavulanate.

14:15Prokinetics have limited evidence, and one old choice has fallen away. Prucalopride, two milligrams daily, or one milligram over age sixty-five, speeds transit through the stomach, small bowel, and colon, and it's the preferred prokinetic. Pyridostigmine, up to thirty milligrams twice a day, improves transit by boosting cholinergic signaling. Octreotide, fifty micrograms subcutaneously at bedtime, was once used in scleroderma to trigger phase three activity. It's no longer broadly recommended, because it slows small bowel transit in healthy people and may worsen overgrowth. Erythromycin helps acute flares but stops working with chronic use. Steroids are reserved for inflammatory neuropathies.

14:57The most severe disease has surgical options, each with a cost. A venting enterostomy relieves massively distended loops. Removing most of the small bowel is reserved for intractable pain from dilated bowel and commits the patient to lifelong parenteral nutrition. Small bowel transplantation is offered to a few selected patients with intestinal failure whose parenteral nutrition has failed, through line infections, loss of venous access, or liver disease. It carries more rejection, graft-versus-host disease, and lymphoproliferative disorders than other transplants.

15:30She starts rotating antibiotics and prucalopride, and a combined venting and feeding tube is placed. Her diarrhea improves, she stops vomiting, and her weight stabilizes.

15:42The fourth patient shows the cause of pseudo-obstruction that must not be missed. A sixty-six-year-old man who smokes, previously healthy, has three months of rapidly worsening distension, vomiting, and constipation, with thirty pounds of weight loss, far more than his symptoms explain. CT shows dilated small bowel with no transition point. He has numb hands and feet. A previously healthy patient over fifty with new, rapidly progressive dysmotility and disproportionate weight loss has paraneoplastic pseudo-obstruction until proven otherwise.

16:17His antibodies point to the tumor. His paraneoplastic panel is positive for antineuronal nuclear antibody type one, ANNA-1, also called anti-Hu, and a chest CT finds a small cell lung cancer, though sometimes only a positron emission tomography, PET, scan finds it. His numb hands and feet are a paraneoplastic sensory neuropathy, and the exam can also show cerebellar findings.

16:40The panel and the tumors are broader than his case. Other antibodies on the panel include anti-CV2, also called CRMP5, antineuronal nuclear antibody type two, Purkinje cell cytoplasmic antibody type one, PCA-1, and N-type calcium channel antibodies. Thymoma, breast cancer, and carcinoid can cause it too. Treating the cancer can stabilize or partly improve the dysmotility, though full recovery is uncommon.

17:11The fifth patient's symptoms come from the stomach, with no structural cause found. A twenty-nine-year-old woman has a year of feeling full after a few bites, uncomfortable fullness after normal-sized meals, and nausea, most days of the week. She's lost eleven pounds, about eight percent of her weight. She takes no nonsteroidal anti-inflammatory drugs, NSAIDs, iron, or other medications. She has no trouble swallowing, no vomiting, no bleeding, and no family history of stomach or esophageal cancer. Her exam is normal.

17:45Her symptoms fit functional dyspepsia, provisionally, because the definition requires that structural disease be excluded. By the Rome criteria, functional dyspepsia is one or more of four bothersome symptoms, postprandial fullness, early satiation, epigastric pain, or epigastric burning, with no structural disease likely to explain them. They must be present for the last three months, with onset at least six months earlier. It affects five to eleven percent of people worldwide, and up to forty percent of those affected seek care.

18:17Her dominant symptom sets her subtype, and the subtype guides treatment. Postprandial distress syndrome is dominated by fullness after meals and early satiation, at least three days a week. Epigastric pain syndrome is dominated by epigastric pain or burning, at least one day a week. Many patients overlap, but she has postprandial distress.

18:38The subtype points to the mechanism. Postprandial distress reflects impaired accommodation, a stomach that doesn't relax to receive a meal, and heightened sensitivity to distension. Epigastric pain reflects visceral hypersensitivity and possibly subtle inflammation. About eighty percent of patients with dyspepsia have no structural explanation, and one patient can have several mechanisms. Impaired accommodation is found in about a third, delayed emptying in a smaller share, and over eighty-five percent of gastroparesis patients also meet criteria for functional dyspepsia.

19:12Other mechanisms add to the picture, and they explain why symptoms can't decide the diagnosis. There's low-grade duodenal inflammation with eosinophils, changes in permeability and the microbiome, onset after gastroenteritis in ten to twenty percent, and disordered gut-brain signaling, with anxiety and depression common. Symptoms alone don't reliably separate functional from structural disease.

19:37Excluding structural disease is the next step, and the differential is broad. It includes peptic ulcer, gastric and esophageal cancer, gastroparesis, gallstones, and drug-induced dyspepsia from NSAIDs, iron, angiotensin-converting enzyme, ACE, inhibitors, or bisphosphonates. It also includes chronic pancreatitis, pancreatic cancer, parasites, liver cancer, chronic mesenteric ischemia, Crohn disease, and infiltrative diseases such as sarcoidosis.

20:12Whether that means endoscopy now depends on age and alarm features. The alarm features are unintentional weight loss of more than five percent over six to twelve months; progressive dysphagia or odynophagia; unexplained iron deficiency or bleeding; persistent vomiting; a family history of upper gastrointestinal, GI, cancer; an abdominal mass or enlarged nodes; and new symptoms at age sixty or older, with some guidelines using fifty-five. Any one means endoscopy first.

20:44She's young, but she's lost eight percent of her weight, so she has endoscopy first, with biopsies. It's normal, and gastric biopsies are negative for H. pylori. Her medication history mattered too, because an NSAID, iron, an ACE inhibitor, or a bisphosphonate would have pointed to drug-induced dyspepsia. With structural disease excluded, the subtype is treated.

21:12First-line treatment for both subtypes is acid suppression, a standard-dose proton pump inhibitor, PPI, for four to eight weeks. It works more reliably for epigastric pain but is tried in postprandial distress too. If it doesn't work at standard dose, it's stopped, because doubling the dose doesn't improve response.

21:30H. pylori eradication is given to every positive patient, whatever the subtype. The benefit is small, sustained improvement in five to ten percent, but it's the only treatment with a lasting effect on an underlying cause. She takes omeprazole twenty milligrams before breakfast for eight weeks, correctly timed, with no change, so it's stopped.

21:51With the PPI failed, her postprandial distress is treated by mechanism. A prokinetic speeds emptying. Metoclopramide, five to ten milligrams three times a day for four weeks, is the Food and Drug Administration, FDA, approved option, with the same twelve-week limit for tardive dyskinesia as in gastroparesis. Acotiamide, a cholinesterase inhibitor, and itopride, a dopamine blocker with cholinesterase inhibition, are used in other countries but aren't approved in the United States.

22:22A fundic relaxant targets accommodation instead. Buspirone, a serotonin one A agonist, ten milligrams three times a day before meals, relaxes the upper stomach and suits early satiety from poor accommodation. The American Gastroenterological Association, AGA, is conditionally against routine use, though it remains reasonable when poor accommodation dominates.

22:44Her weight loss makes one neuromodulator the best fit. Mirtazapine blocks serotonin three and histamine one receptors, so it treats nausea and stimulates appetite, which suits a thin patient with early satiety and weight loss. It starts at seven and a half milligrams at bedtime and goes up to fifteen to thirty. Smaller meals, avoiding high-fat or high-FODMAP triggers, and moderating alcohol help some patients, though the evidence is limited.

23:10She starts mirtazapine at bedtime and eats smaller meals, and over three months her nausea settles, her early satiety eases, and she regains six pounds.

23:20Without a response, two more options apply to both subtypes. Psychological therapies, cognitive behavioral therapy, gut-directed hypnotherapy, and mindfulness-based therapy, reduce symptoms whether or not anxiety or depression is present, and guidelines recommend considering them after drugs fail. An herbal preparation, STW five, sold as Iberogast, has trial support for postprandial distress. Acupuncture and ginger have weaker evidence.

23:48Her long-term course is uncertain, which shapes follow-up. Over the years, about half of patients have persistent symptoms, and only a minority resolve completely. Symptom severity is the strongest predictor of health care use and disability. Once symptoms are stable, a trial of stopping the PPI every six to twelve months is reasonable, because a meaningful proportion of patients can come off it.

24:10The last patient shows that the other subtype has a simpler path. A thirty-four-year-old man has had epigastric burning and gnawing pain for eight months, a few days a week, sometimes after meals and sometimes not, with no alarm features. Under sixty without alarm features, endoscopy isn't the first step. He's tested for H. pylori noninvasively and treated if positive. If he's negative, or if symptoms persist after eradication, he gets a standard-dose PPI for four to eight weeks.

24:40His stool antigen is negative, and omeprazole twenty milligrams before breakfast for eight weeks improves his burning substantially, in the subtype the PPI helps most. A trial of stepping down or stopping the PPI is planned every six to twelve months.

24:55Refractory epigastric pain would have its own next step. It would get a low-dose tricyclic, amitriptyline, nortriptyline, or imipramine, ten to fifty milligrams at bedtime. That reduces visceral hypersensitivity, with a number needed to treat of about six, judged over eight to twelve weeks. Selective serotonin reuptake inhibitors, SSRIs, and serotonin-norepinephrine reuptake inhibitors, SNRIs, haven't shown reliable benefit and aren't first-line.

25:25Here are the traps the boards set in these patients. Stereotyped attacks with normal intervals aren't gastroparesis, and a patient nauseated most days doesn't have cyclic vomiting. The migraine history isn't missed. Cannabis, hot showers, and eating and weight are always asked about. A tricyclic isn't started in a daily cannabis user with hot-shower relief, and ondansetron doesn't control cannabis hyperemesis.

25:49The pseudo-obstruction traps follow. Recurrent obstruction with no transition point isn't operated on, but pseudo-obstruction isn't called until a mechanical cause is excluded. The search for a secondary cause isn't skipped, megaduodenum isn't missed in scleroderma, and a paraneoplastic syndrome isn't missed in an older smoker with rapid weight loss. Feeding goes into the jejunum, not a stomach that doesn't empty. Bacterial overgrowth isn't forgotten, octreotide isn't a routine prokinetic, and an opioid isn't left in place.

26:21The dyspepsia traps close the list. Weight loss is an alarm feature even in a young patient. A young patient without alarm features isn't scoped first, because test and treat for H. pylori comes first. A PPI that failed at standard dose isn't doubled. An SSRI isn't the neuromodulator of choice, a tricyclic isn't judged too early, and mirtazapine is the fit for weight loss.

26:45So, start to finish. Stereotyped vomiting attacks with normal intervals are cyclic vomiting syndrome or cannabinoid hyperemesis syndrome. Cyclic vomiting has migraine biology, so prevent it with amitriptyline or nortriptyline and lifestyle changes, and treat attacks with fluids, antiemetics, benzodiazepines, and triptans. Cannabis hyperemesis follows years of use, comes with relief from hot showers, and resolves only with stopping cannabis.

27:16Pseudo-obstruction is obstruction without a lesion. Exclude a mechanical cause, confirm dysmotility, separate neuropathic from myopathic disease with antroduodenal manometry, and search for a cause, including scleroderma with megaduodenum and anti-Hu paraneoplastic disease. Treat with jejunal feeding and venting, parenteral nutrition when needed, rotating antibiotics, and prucalopride or pyridostigmine.

27:40Functional dyspepsia is fullness, early satiation, or epigastric pain or burning without a structural cause, split into postprandial distress and epigastric pain subtypes. Under sixty without alarm features, test and treat H. pylori, then give a standard-dose PPI. At sixty or older, or with any alarm feature, scope first.

28:02Then match treatment to the subtype: a PPI for epigastric pain, a prokinetic or buspirone for postprandial distress, mirtazapine with weight loss, and a low-dose tricyclic for refractory pain.

28:15The next chapter is upper GI bleeding: resuscitation and the steps before endoscopy, anticoagulants and antiplatelets, endoscopic findings and treatment, and the PPI strategy that prevents rebleeding.

28:28For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode two of two of chapter eight, and I'll see you in the next one.