Nintedanib and Capecitabine in Treating Patients With Refractory Metastatic Colorectal Cancer

Inclusion Criteria: * Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 * Hemoglobin \>= 9 g/dL * Absolute neutrophil count \>= 1500/mm\^3 * Platelet count \>= 100,000/mm\^3 * Creatinine =\< 1.5 upper limit of normal (ULN) AND creatinine clearance (CrCl) \> 50 mL/min by Cockcroft-Gault equation * Males = (140 -age (yrs) (body weight (kg)/(72) (serum creatinine) (mg/dL) * Females = 0.85 \* (140-age (yrs) (body weight (kg)/(72)(serum creatinine (mg/dL) * Bilirubin \< ULN * Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =\< 1.5 ULN if without liver metastases * AST/ALT =\< 2.5 x ULN if with liver metastases * Coagulation parameters: international normalized ratio (INR) =\< 2, prothrombin time (PT) and partial thromboplastin time (PTT) \< 1.5 X institutional ULN * Have measurable disease per RECIST 1.1 criteria * Histologically or cytologically proven adenocarcinoma of the colon or rectum * Prior progression following a fluoropyrimidine-based therapy and progression following or intolerance to irinotecan and oxaliplatin, as well as anti-epidermal growth factor receptor (EGFR) therapy (e.g., panitumumab or cetuximab) for rat sarcoma viral oncogene homolog (RAS) wild-type patients * Ability to swallow and retain oral medication * Participants of child-bearing potential must agree to use adequate contraceptive methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study entry and for three months following completion of therapy; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately * Participant or legal representative must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent form prior to receiving any study related procedure Exclusion Criteria: * Prior treatment with nintedanib * Prior treatment with regorafenib * Major injuries or surgery within the 4 weeks prior to initiation of therapy with incomplete wound healing or planned surgery during the on-study treatment period * Uncontrolled hypertension: systolic blood pressure \>= 160, diastolic blood pressure \>= 90 * Urine protein/creatinine ratio \>= 1.0 * History of clinically significant hemorrhagic or thrombotic event within the past 6 months, not including uncomplicated catheter-associated venous thrombosis; patients on anti-coagulation are not permitted to be on any oral formulations (warfarin, rivaroxaban, dabigatran, etc.) due to concern for drug-drug interaction * Unstable angina, symptomatic congestive heart failure or cardiac arrhythmia requiring anti-arrhythmic therapy (beta-blockers, calcium channel blockers and digoxin are allowed) * History of cerebrovascular or myocardial ischemia within 6 months of initiation * Known inherited predisposition to bleeding or thrombosis * Known active or chronic hepatitis B or C or human immunodeficiency virus (HIV) * Untreated brain metastases * History of second primary malignancy diagnosed within 3 years prior to enrollment, excluding: * In-situ cervical carcinoma * Superficial bladder cancer * Non-melanoma skin cancer * Stage I breast cancer * Low grade (Gleason =\< 6) localized prostate cancer * Any additional malignancy which has been in clinical remission for at least 1 year * Pregnant or nursing female participants * Unwilling or unable to follow protocol requirements * Any condition which in the Investigator's opinion deems the participant an unsuitable candidate to receive study drug * Received an investigational agent within 4 weeks prior to enrollment * PHASE I: History of intolerance to capecitabine at doses =\< 1000 mg/m\^2 BID, as defined by documented \>= grade 3 hand-foot syndrome, documented severe diarrhea requiring hospitalization, or other documented severe adverse events (AEs) attributable to capecitabine * PHASE II: History of intolerance to capecitabine at doses below 1000 mg/m\^2 BID, as defined by documented \>= grade 3 hand-foot syndrome; documented severe diarrhea requiring hospitalization; or other documented severe AEs attributable to capecitabine