PAM

A 55 yrs old man with CD underwent ilial resection. The surgical procedure was uneventful. 3 months later, he was reviewed in the clinic . His apitite remain good and the abd pain has settled,but he was troubled with diarrhoea with day time frequency 6/day. He also experienced faecal urgency 20-40 min after eating. The stool was watery but no blood or mucous.

investigation:
Hb 125
WCC 5.6
Plt 256
ESR 12
B12 340 (160-760)
folate 420 (160-640)

What is the most likely cause for the diarrhoea:
1-Bacterial overgrowth
2-Bile salt malabsorption
3-Enterocolic fistula
4-Lactase def
5-Recurrent CD

Bile salt metabolism. my gastro room blog

Bile acids recirculate between the liver and small intestine in the enterohepatic circulation. Around 95% reabsorbed in the treminal ileum, and normally only a small fraction of the bile acid pool is lost to the colon during each cycle. 

In patients with bile acid malabsorption, a larger amount of bile acids is spilled into the colon, where the acids stimulate electrolyte and water secretion, which results in loose to watery stools. 

The common causes of bile acid malabsorption are:

ileal resection and diseases of the terminal ileum (Crohn's disease and radiation enteritis), which result in a loss of bile acid transporters and, consequently, diminished reabsorption. 

Bile acid malabsorption also has been documented in a small group of patients with chronic, watery diarrhea who have no demonstrable ileal disease (idiopathic bile acid malabsorption). 

The amount of bile acid loss to the colon determines the clinical presentation. 

Patients with bile acid malabsorption typically present with chronic, watery diarrhea. 

Other symptoms include:Bloating, abd discomfort and steatorrhea due to fat malabsorption.

The BSG guidelines for assessing of PAM:

1-Measurment of the turnover of radiolabelled bile acid:

14C-glycocholate in the stool over 48-72 hrs after ingestion of the marker

2-Measurment of serum metabolites:

avoid the use of radiolabels and correlate with SeHCAT results

3-Quantification of excreted bile acid by the selenium 75-labelled homotaurochlolic acid test SeHCAT : values <15 font="" of="" pam="" suggestive="">

3 days treatment trail can be an indication of PAM

Cholestyramine, cholestipol and colesevelam.

causes of PAM, my gastro room blog