Gemcitabine and Capecitabine in Treating Patients With Advanced and/or Inoperable Cholangiocarcinoma or Carcinoma of the Gallbladder

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed cholangiocarcinoma or carcinoma of the gallbladder * Advanced and/or inoperable disease * Measurable disease * At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * No known brain metastases PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 OR * Karnofsky 60-100% Life expectancy * More than 2 months Hematopoietic * WBC ≥ 3,000/mm\^3 * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 Hepatic * Bilirubin \< 3 mg/dL Renal * Creatinine ≤ 1.6 mg/dL Cardiovascular * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No prior allergic reaction attributed to compounds of similar chemical or biological composition to study drugs * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No other concurrent uncontrolled illness PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * More than 4 weeks since prior chemotherapy and recovered * No more than 1 prior chemoembolization OR chemoradiotherapy regimen for locally advanced biliary tract cancer * No other prior chemotherapy (except adjuvant therapy) Endocrine therapy * Not specified Radiotherapy * See Chemotherapy * More than 4 weeks since prior radiotherapy and recovered Surgery * Not specified Other * No other concurrent investigational agents * No other concurrent anticancer agents or therapies