Digestive System
Online Learning Platform

If someone has IgA deficiency and celiac disease, the IgA deficiency can cause a false negative on a celiac disease antibody test.  (As IgA anti transglutaminase antibodies may be falsely normal) In this case it is important to perform IgG-specific antibody tests for endomysium, gliadin, and tissue transglutaminase

It is expected that up to 1 in 2 patients who are positive in faecal inmunochemistry test  (FIT) can have pathology (polyps or cancer) This can be seen in  results such as the QUALISCOPIA group or the UK bowel screening  report

Misty mesentery refers to a non-specific radiological finding characterized by increased attenuation within the mesenteric fat on computed tomography  imaging.  It mimics mistiness as localised fat stranding in the mesentery.  Many processes can lead to the appearance including infiltration by inflammatory cells, oedema, lymphatic accumulation, haemorrhage, tumour infiltration, and fibrosis.  Tipically reflects mesentery panniculitis  ( rare  benign condition characterized by chronic inflammation  of adipose tissue mainly of the small bowel mesentery) But can be the results of any inflammatory or neoplasic process. That is why it is needed to consider also vasculitis, lymphomas, inflammatory process or GI neoplasia.

High Amplitude propagating contractions (HAPC)

• HAPC, Defined by high amplitude (variable threshold among studies) and presence of propagation; amplitude is higher in the prepped than unprepped colon
•  from 50-100, can reach up  to 200 mm Hg, they last 20 to 30 seconds, approximately 6 times a day, with a range of 2 to 24 daily.
• Occur spontaneously, in response to pharmacological agents or colonic distention
• Increase upon awakening, are much more common during the day, and increase after meals
• A majority originate in the proximal colon; most do not propagate beyond the midcolon and fewer than 5% reach the rectum
• Can transfer colonic contents over long distances, can be associated with internal anal sphincter relaxation, and can precede defecation

Low amplitude (Haustral Contractions)

• Slow, segmenting movements that further mix chyme.
• About every 30 minutes.
• (5 to 40 mm Hg) 3 seconds
• Occur in haustra: small pouches caused by the teniae coli (longitudinal smooth muscle ribbons that run along outside the entire length of the colon). Because they are shorter than the large intestine, the large intestine tucks between the teniae and form sacs
• Primarily occur in ascending and transverse colons.
• Produced by contractions of smooth muscle layer

Both the low- and high-amplitude contractions are promoted by physical exercise as well as by emotional stress.

It is known that HAPC reduce  over time in elderly patients, and also are notoriously reduced in frequency in those wih chronic constipation. Opposingly they are increased in diarrhoea type IBS.  Low amplitude are worse understood, and despite increasing with age, they do not usually change the transit time.

Source

Source 2

Anatomy and Physiology of the Pelvic Digestive Organs
Ursula Szmulowicz MD, in
Posterior Pelvic Floor Abnormalities
, 2011

based on the American Association for the study of liver diseases  guidelines

Check the guidelines

It has always been agreed that High grade dysplasia should merit ablation, however clasically LGD would be offered endoscopic surveillance until progressed to HGD. This approach has changed over the last years to the point that Both ESGE and AGA suggest eradication with ablation to prevent progression to HGD/cancer. BSG recommends repeating endoscopy in 6 months and if confirmed again, offering eradication vs 6 -monthly surveillance.  The AGA 2024 guidelines favous ablation over surveillance.

All societies agree that he biopsies should be reviewed by an expert pathologist (ESGE suggest 2 experts) before embarking into eradication.  Remember that the incidence of progression (to HGD or adenoca) is estimated around   9.1%/year  with reported incidence of adenocarcinoma of 0.54% per year. The overall yearly incidence of Eosphageal adenocarcinoma is 0.3% (0.19 in short segment )

Hb needs to be kept 7-8g/dl at least,  and a target of >9-10g/dl  if significant cardiovascular disease.  Andenaxet is recommended if life threatening or uncontrolled bleeding, like this case which is responding only partially to resucitation with fluids and continues to pass blood, so it could be prescribed.  If not available, 4-F PCC can be used instead.  Urgent sigmoidoscopy in general has no role and it would likely be useless without an adequate bowel preparation as we would expect to have very poor visibility due to stool and blood remains.

Unprepped colonoscopy or any form of sigmoidoscopy is NOT recommended in acute lower GI Bleeding unless very clear that the source is known to be anorectal or very distal colon (see American Guidelines) BSG guidelines also recommneds Colonoscopy as  inpatient with adequate bowel preparation, not urgently but  ideally after stabilising the patient.

If after resucitation and transfusion the patient remains unstable, then a joined plan with intensivist and surgical colleagues should be made (i.e, Interventional radiology, vs quick preparation with movicol, vs enema and salvage lower endoscopy, vs surgical approach)

Andexanet is factor Xa inhibitor which is approved to reverse Rivaroxaban and Apixaban. However, it has not being proved to be efficacious against Edoxaban. Dabigatran is  a direct thrombin (factor IIa) inhibitor, not a Xa inhibitor.

Check AGA guidelines and ESGE, BSG  and Asia Pacific and  international consensus group

This is a Forrest III (clean based) duodenal ulcer in a healthy and stable patient. (Rebleeding risk <5% )

Patient could be discharged if stable and toleranting oral diet (AGA recommends in low risk endoscopic findings considerning discharge in stable cases with stable vitals and Hb and  no other reason for hospitalization).  PPI should be initiated orally, but given it is a low risk finding (F-III) only standard dose would be enough.  If it was a high risk such as Forrest I-IIa, then 72h of  IV PPI (Or oral high dose PPI in selected cases) is recommended as well as keeping the patient under observation.

In high risk (Forrest I-IIb) American and International guidelines advise commencing a two week course of twice daily high dose PPI,  based on a trial that showed 40 mg esomeprazole BD significantly reduced rebleeding compared  40 mg esomeprazole once daily  ( 10.8% v 28.7%,)

So the endoscopist gave good advice in general. So why is it false then? Because:

•  ESGE recommends in bleeding secondary to peptic ulceration,H pylori test at index endoscopy.   In the event of a negative result,  like this case, advise  retesting within four weeks and eradication of H pylori if positive (given the low-ish sensitivity of clotest or histology in acute bleeding, about 0.7)
• Do not forget iron replacement, either orally or if patient does not tolerate, then iron infusion to correct the anaemia.
• Smoke cessation is advised too!  Especially if Hpylori is really negative, then smoking could be a main trigger factor.