welcome to HCM,
If the gastroenterologist is suspecting blockage there has to be reason for him to suspect that, based on investigation reports. Probably the patients serum bilirubin
is not coming down or gradually increasing. Thickening of duodenum
may cause blockage of biliary tract drainage
by squeezing effect on the common bile duct at the point where it enters the duodenum.
Wishing the patient all the best.