Chronic diarrhea is used to define a diarrhea which lasts more than four weeks [1] and differential diagnosis is quite widely [2]. Cholescystectomy is considered to be one of its causes, which is estimated to appear in about 30% of patients who undergo this surgical procedure [3]. Nevertheless, diarrhea could be improved even reducing blood cholesterol levels, modifying dietetic habits, or using bile salts or cholesterol chelation therapy.

Post cholescystectomy diarrhea could go unnoticed in daily clinical practice even though physiopathological mechanisms involved in this process were described 30 years ago [4]. We are presenting a 28 year old female patient complaining of chronic diarrhea and weight loss appearing after cholescystectomy and dramatically improving upon resincholestyramine was ordered. Nevertheless, the clinical symptom reappeared when the patient was transiently and voluntary taken off the medication. Many drugs have been considered to produce chronic diarrhea [5] but it is uncommon the fact that a drug might determine a complete recovery.

A 28 year old female patient complaining of 6 months of diarrhea and weight loss was sent for evaluation to our Internal Medicine Department. She refers from 6 to 8 daily bowel movements but no blood, mucus or pus. She also pointed out her symptoms were interfering with her normal life. No relevant personal or family antecedents except for the fact the patient underwent a cholescystectomy a year ago. Gallstone analysis was not consistent with the presence of a subjacent metabolopathy (considering the patient's age).

On physical examination the patient looked ill. Weight was 50 kg and BMI 19.53 kg/m2. She was not febrile. A chemistry panel including blood lipids came back negative, immunoglobulins G, A and M were normal and IgG / IgM ASCA antibodies were negative. Blood was not detected in three stool analyses, Alpha 1 antitrypsine was normal as well as IgA antitransglutaminase, Parasites and stool cultures came back negatives.

The patient was sent for a chest X-rays, abdominal ecography and upper and lower endoscopies. All exams returned normal.

The combination of dietetic regime and loperamide was not successful, therefore the patient was put on 12 grams daily of resincholestyramine at dinner time. Diarrhea slowly improved within the first days after the treatment was started and the patient recovered weight. Treatment was slowly reduced as symptoms improved. In this regard, only four grams of resincholestyramine daily, once per day, were enough to control the symptoms. However, symptoms showed up again three years later after the patient voluntary stopped the medication (the patient referred she was not comfortable taking that medication at her age). Resincholestyramine was reintroduced and diarrhea was quickly controlled.

Bile salts are secreted by the gallbladder during digestion and reabsorbed in the terminal ileon. They are involved in the digestion of lipids [6]. After cholescystectomy, bile salts are not stored but continuously drained by the liver into the small bowel. This continuous secretion of bile salts into the small bowel is at the origin of water and electrolytes disturbances. A similar situation is present when a vagotomy is performed because bowel movements are faster and there are more bile salts [4].

Cholescystectomy is considered to be an important medical antecedent in patients suffering from chronic diarrhea [3]. Diarrhea may appear, generally, from some months to years after the gallbladder is removed which makes physician take into account the wide range of differential diagnosis of chronic diarrhea. In this respect, inflammatory bowel diseases, tumors, infections, malabsorption syndrome, metabolic disorders, treatment with certain drugs and systemic conditions must be ruled out [2].

Once the previous medical conditions have been ruled out, medical treatment with cholestyramine may be tested. Cholestramine is an ion exchange resin acting in the bowel [7]. Doses recommended range from four to two grams per day even though, as in our case, some clinical essays have reported this drug could also be effective if taken once a day. Bile salts are considered to play an important pathogenic role in chronic diarrhea of unknown origin once malabsorption [8, 9], irritable colon [5] and lactase deficiency [10] have been ruled out.

Management of chronic diarrhea is complex considering the wide range of causes. Personal antecedents must carefully be collected and taken into consideration in order to come up with a correct diagnosis.

Chronic diarrhea appears in approximately 30% patients after cholescystectomy, thus this antecedent is relevant if we consider the high prevalence of gallstones in the general population.

Some biochemical markers evaluated together with the clinical situation may be of use in the diagnosis of diarrhea due to the excess of bile salts before drugs are tested [10].