Slowing or cessation of activity:

• esophagus: swallowing problems (dysphagia & measure with barium swallow &/or manometry)
  • mechanical:
    1. acute: viral & fungal (candida) esophagitis.
    2. chronic:
       • achalasia: term used for apparent distal obstructions but is more specific after EGD for obstruction apparently due to increased distal sphincter tone (functional achalasia ?) & often with some dilation of esophagus.
       • Schatzki ring: an organic partially obstructing membrane.
       • stricture/stenosis:
         1. benign
         2. malignant
  • non-mechanical:
    1. acute:
       • esophagoparesis (organic vs. functional)
    2. chronic:
       • globus<: functional disorder = sensation of lump or tightness in throat; may be as recurrent acute episodes.
       • functional dysphagia: absence of clinical or histological evidence of GERD or other organic disorder.
       • chronic pseudo-obstruction (e. g., scleroderma/CREST).
       • organic deposits: hemochromatosis, amyloidosis, etc.
• stomach: emptying problems (measure with post-fasting food present at EGD or, gastroduodenal manometry, or SITZMARKS study, or gastric emptying study)
  • mechanical:
    1. acute:
       • prolapse
       • distal ulcer
       • as complication of not-previously obstructive chronic lesion
    2. chronic: (a combination of EGD findings and insertion of SITZMARKS capsules or capsule endoscopy distal to the suspected obstruction to show that rest of bowel has normal transit time)
       • distal tumor, ulcer
       • hypertrophic pyloric sphincter
       • chronic pseudo-obstruction (e. g., scleroderma/CREST)
  • non-mechanical:
    1. acute:
       • gastroparesis: at level of CNS, autonomic, enteric nervous systems via traumatic, toxic, metabolic, medicinal, infectious, degenerative, and autoimmune etiologies (diabetes is most common cause).
       • gastromalacia: at autopsy one may find areas of marked mural gastric thinning...sometimes perforated (considered to be an agonal dissolution of the mural tissue).
    2. chronic:
       • gastroparesis: diabetes ("gastroparesis diabeticorum"...L-06-7445, L-07-1465) is a most common cause & etiology of gastroparesis (autoimmune& others...see acute, above) & diagnosed in nuclear medicine with meal of scrambled eggs containing a tracer; usually, half of activity has passed out of stomach within 90 minutes. If longer than 110 minutes to half empty, abnormal. Chronic pseudo-obstruction (see histology below) can be a gastroparesis cause. A combination of EGD findings and insertion of SITZMARKS capsules or capsule endoscopy distal to the sphincter or distal duodenum to show that rest of bowel has normal transit time. As with acute, there are many potential etiologies. By 2009, treated by dietary modification & maybe OTC domperidone (Motilium) or maybe Reglan.
       • excessive belching disorders: true aerophagia vs. functional.
       • nausea & vomiting disorders: when one is bothered several times per week with nasea & EGD is normal = " chronic idiopathic nausea"; "functional vomiting" is an average of an episode per week of vomiting that is in absence of chronic canabinoid use, absence of major psychiatric disorder or an eating disorder or rumination syndrome & negativity for CNS or metabolic disorder or abnormal EGD. "Cyclic vomiting" is 3 or more episodes per year of acute vomiting lasting a week or less (usually a family HX of migraines).
       • rumination syndrome in adults: when one recurringly burps up or regurgitates partly digested food into the mouth with spitting it out or rechewing & reswallowing. Differs from GERD in that tends to be before food has become acidic.
    3. organic deposits: hemochromatosis, amyloidosis, etc.
• duodeno-enteric: emptying or slow transit problems (measure with malabsorption tests or possibly capsule endoscopy).
  • mechanical:
    1. acute: when significantly myopathic, can result in elevated CPK.
       • volvulous/incarceration: myopathic effect will tend to affect lumenad components worse than mural periphery (such as muscularis propria externa) [L-06-9956].
       • stricture/ulcer: as with volvulous.
       • torsion/incarceration: as with volvulous.
       • external obstruction/incarderation: adhesions, endometriosis, etc.; changes as with volvulous.
    2. subacute & chronic:
       • the above causes of acute: but at a slower temporal profile.
       • chronic pseudo-obstruction: (e. g., scleroderma/CREST).
  • non-mechanical:
    1. acute:
       • duodenoparesis, enteroparesis: potential same causes as acute or chronic gastroparesis & rarely just as an isolated segment. In fact, though there may be a worst segment, paresis beyond the stomach likely to effect entire tract...enterocoloparesis.
       • enteromegally: Ogilvie's syndrome (colonic is more common)
       • "ileus" (adynamic ileus): due to effects of shock and/or anesthesia or operative-associated medications.
       • vague etiologies: at level of CNS, autonomic, enteric nervous systems via traumatic, toxic, vascular insufficiency (FA08-139), metabolic, medicinal, infectious, degenerative, and autoimmune etiologies.
    2. chronic:
       • chronic intestinal pseudo-obstruction¹: see colonic, below.
       • irritable bowel syndrome (IBS): any duodeno-enteric component of IBS.
       • vague etiologies: at level of CNS, autonomic, enteric nervous systems via traumatic, toxic, metabolic, medicinal, infectious, degenerative, and autoimmune etiologies.
    3. with organic deposits: hemochromatosis, amyloidosis (L-06-6141), etc.
• colonic/rectal: slow or rapid transit and pain & urgency problems (measure with transit time measures such as the SITZMARKS radiopaque rings sequence; rectal function with anorectal manometry or ability to expell an inserted baloon). Chronic constipation (category includes Rome III criteria "functional defecation disorder") falls into this category and consists of 2 main types: (1) obstructed defecation and (2) slow transit...traditionally thought due to recto-anal dysfunction (pelvic flow failure to relax, paradoxical floor contraction, defective or deficient rectal motor function and/or sensitivity⁴.
  • mechanical:
    1. acute:
       • fecal impaction/constipation, with or without stercoral ulcer; volvulus of dilated bowel [L06-8447; L07-10934]. May see myopathic degeneration. See enteric acute volvulous, above.
    2. chronic:
    • histologically unremarkable: this suggests mechanical etiology likely (1) "functional defecation disorder" or (2) slow transit due to "obstructed defecation" of recto-anal dysfunction (pelvic flow failure to relax, paradoxical floor contraction, defective or deficient rectal motor function and/or sensitivity).
    • stenosis: chronic stenosing diverticulitis; IBD-C; neoplasia/tumor; mural constricting scar; externally occlusive adhesion.
    • dolichocolon or redundant colon: abnormally long colon with chronic low-grade incompletely occlusive torsion.
    • diverticulosis/diverticulitis: diverticular protrusions probably secondary to effects of chronic malcoordinated peristalsis; as blind pockets of intestine, they are subject to acute & chronic inflammation with abscess production and even perforation. Strangely, even when not really inflammed, they are subject to bleeding of significant...event emergent... degrees, without one always finding a macroscopic bleed site when examining the colectomy specimen (often associated with chronic aspirin intake). Bleeding may be appreciated microscopically as RBCs mixed with lumenal mucous [L06-9851] in the diverticula. Associated muscular hypertrophy can cause a setting leading to a colitis within the segment that looks like IBD-UC, microscopically.
  • non-mechanical:
    1. acute:
       • colonoparesis: potential same causes as gastroparesis & rarely just as an isolated segment; if so problematic as to require hospital-based treatment, best to use the term "acute pseudo-obstruction".
       • acute idiopathic pseudo-obstruction (nontoxic megacolon) [mega= enlarged/dilated]...Ogilvie's syndrome¹; studies have documented that up to 95% of the cases of acute colonic pseudo-obstruction are associated with medical [LMC-05-9716 venous congestion, mucosal hemorrhage & then localized pseudomembraneous colitis] or surgical conditions (secondary), with the rest being classified as idiopathic, sometimes with myopathic "pseudo-obstruction" [L07-8628]. The most commonly associated conditions for secondary etiology include trauma, pregnancy, cesarean delivery, severe infections, and cardiothoracic, pelvic, or orthopedic surgery². This degeneration can be very focal & acute, subacute, or chronic and a basis for colonoscopic pneumatic perforation [L08-13361].
       • toxic megacolon:
         • Hirschsprung's complicated:
         • ulcerative colitis (IBD-UC) complicated:
         • ischemic colonopathy/colitis complicated:
         • pseudomembraneous colitis complicated:
         • chronic intestinal pseudo-obstruction complicated:
    2. chronic:
       • chronic inertia: absence of our diagnosing any of the below diagnoses in a patient with slow transit time and medically refractory constipation [L-05-2255]. May be diagnosed by oral ingestion of a "SITZMARKS diagnostic test" capsule containing 24 radiopaque rings & transit time checked. See vague etiologies, above, with gastroparesis & enteroparesis.
       • Hirschsprung's disease: as pediatric or child or even adult onset...histology of full thickness biopsy in search of intestinal neuronal dysplasia (IND)...decrease or loss of ganglion cells & other abnormalities of myenteric innervation. Meissner's plexus just beneath the muscularis mucosae normally has a small cluster of, say, 1-5 ganglion cells for about every 1mm of length [L07-2013]. Auerbach's plexus between the interna and externa layers of the muscularis propria normally has a regularly intermittently visible nueral zone with fibers and ganglion cells. If ganglion cells seem decreased or absent, look for hypertrophy (increased prominence) of the tiny nerves in the plexi.
       • zonal colonic aganglionosis (ZCA): motility dysfunction (constipation) which is due to patchy loss of ganglia [L07-2992; may see ZCA & CIPO combo L07-10605] and therefore harder to diagnose.
       • intestinal neuronal dysplasia: hyperplastic...even giant...ganglion cells⁴.
       • obstructed defecation, colonic type: one finds enteric S100-pos. glial cell loss (a cell which "orchestrates motility") & reduced NSE-pos. neuroganglionic cells in superficial plexus...possibly explains lake of this variant of obstructed defecation to respond to biofeedback therapy⁴.
       • cathartic colon: melanosis coli [L07-2992, L09-11652], when demonstrated, can imply this designation which is a sign that there is some as yet undiagnosed cause for laxative medication.
       • megacolon or megarectum: congenital, acquired, idiopathic (due to infectious or other neurological disease, systemic disease, metabolic disorders, medication or drug effects...Chagas disease is most common world-wide cause)[LMC-02-5403].
       • dolichocolon or redundant colon: abnormally long colon.
       • chronic intestinal pseudo-obstruction (CIPO): idiopathic (primary) or secondary (long outline of causes) dilated colon with thin walls (colonic atrophy, mural atrophy, "leiomalacia") [LMC-05-8635] to dilated but mostly normal (L06-8447; L07-10605) to stiff colon with thick muscular wall (mural colon hypertrophy) [LMC-04-8885; LMC-04-9493; L-05-2533]. Can just affect part of a colonic area. Always some dilatation with variable smoothing of mucosal folds and usually thick & thin areas of muscularis propria. The muscularis propria is normally 2-3MM thick (about 8-12g/cm of colonic length with most of paracolic tissue trimmed off). May be secondarily complicated by stercoral ulcers (or other secondary etiology) with perforation [LMC-07-6010; L07-7094]; could perforate following colonic inflation for colonoscopy [L07-6869]. Can be familial or sporadic, segmental to systemic (best review here¹). Don't confuse this disorder with the mural thickening often seen in chronic diverticulosis/diverticulitis, which thickening (1) tends to be closely limited to the diverticular bowel segment, and is (2) negative for myopathic or neuropathic degeneration:
         • myopathic forms: thin...colonomalacia...[LMC-05-8635; LMC-05-9384] or thick walls show muscle degeneration and fibrous replacement. Scleroderma might be a cause.This degeneration can be very focal & acute, subacute, or chronic and a basis for colonoscopic pneumatic perforation [L08-13361].
         • neuropathic forms: reduced or nearly absent enteric neural apparatus and/or ganglia with CMV-like non-viral inclusions.
       • functional disorders:
       • irritable bowel disorder (IBS): abdominal pain which improves with defecation and either predominantly associated with diarrhea IBS-D) or with constipation (IBS-C).
       • functional bloating: in absence of any other functional GI syndrome, patient senses abdominal distension whether it can be measured or not.
       • functional constipation: in persons not fulfilling IBS-C criteria, there is persistently difficult, infrequent, or incomplete defecation.
       • functional diarrhea: at least 75% of stools are mushy or watery and without pain.
       • unspecified functional bowel disorder: cases of b owel symptoms not attributable to an organic etiology and not fitting criteria of the above 1-4.
       • with organic deposits: hemochromatosis, amyloidosis, etc.

Hyperactivity:

• esophagus:
• stomach: "dumping syndrome"
• duodeno-enteric:
• colonic/rectal: diarrhea of all sorts; be aware of the post-"starvation" "Refeeding Syndrome" with possible copious diarrhea, acute dementia, cardiac failure, coma, and convulsions. Re-intake of unregulated carbohydrates too quickly and hypokalemia low potassium likely present.

Combination hyper & malcoordinated defects:

• esophagus:
• stomach:
• duodeno-enteric:
• colonic/rectal:
  • irritable bowel syndrome (IBS): malcoordination and functional

References:

1. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. Odze, Goldblum, & Crawford, 1067 pages, 2004. [EBS]
2. e-Medicine website: http://www.emedicine.com/
3. "ROME III, The Functional Gastrointestinal Disorders", the entire issue of Gastroenterology 130(5):1377-1556, April 2006.
4. Bassotti G, et. al., "Colonic neuropathological aspects in patients with intractable constipation due to obstructed defecation", Modern Pathology 20(3):367-374, March 2007.