A common cause for fatigue after MGB is hypoalbuminemia. She should supplement her diet with protein shakes and protein bars, see a nutritionist every week to make sure she drinks and eat enough.

Depletion of vitamin B1 is very fast. She should take vitamin B complex every day.

Please check if she has developed gall stones by ultrasonography.

If she has frequent bowel movements supplement her with pancreatic enzymes.

I had a patient that developed severe weakness fever and splenomegaly and the cause was infectious mononucleosis due to CMV infection.

Please check also for anastomotic ulcer by gastroscopy.

A psychologist should follow her as well and if she takes psychiatric medications, the doses should be augmented. 

Please look again in the CT scan to be rule out porto mesenteric vein thrombosis, as the presenting symptoms are often vogue. 

C rective protein can give you a hint if there is a physiological  medical problem. If it is normal , usually it is only an adjustment problem. 

Be patient and see her every week until she feels better. 

Don't forget to check B12, folate, ferritin, Vitamin D, and trace metals including copper.  B12 and copper deficiency can lead to peripheral subacute combined degeneration.  A contrast meal may be helpful +/- OGD to check anastomosis.  Occasionally, SIBO may complicate things if she has had a Roux limb, hence useful to rule out with breath test

thankyou

 dear colleague:

B12 deficiency is a main problem in this case.evaluation peripheral blood smear and B12 and folic acid replacment recumended.

thankyou

she developed severe hypo albuminemia with ascites,peripheral eedema and weakness.she is being treated with IV albumin.