Question: What are the main side effects of chemotherapy?
About the article "Chemotherapy", section "Gastrointestinal distress".

Candidate passages:
In the relative spectrum of cancer chemotherapy, ABVD is not a particularly toxic regimen.
Side effects of ABVD can be divided into acute (those occurring while receiving chemotherapy) and delayed (those occurring months to years after completion of chemotherapy).
Delayed side effects have assumed particular importance because many patients treated for Hodgkin lymphoma are cured and can expect long lives after completion of chemotherapy. 
"Supportive care" refers to efforts to prevent or treat side effects of ABVD chemotherapy, and to help patients get through the chemotherapy with the least possible discomfort. 
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is the treatment of cancer with one or more cytotoxic anti-neoplastic drugs (chemotherapeutic agents) as part of a standardized regimen.
Chemotherapy may be given with a curative intent or it may aim to prolong life or to palliate symptoms.
It is often used in conjunction with other cancer treatments, such as radiation therapy, surgery, and/or hyperthermia therapy.
Certain chemotherapeutic agents also have a role in the treatment of other conditions, including ankylosing spondylitis, multiple sclerosis, Crohn's disease, psoriasis, psoriatic arthritis, systemic lupus erythematosus, rheumatoid arthritis, and scleroderma.
Traditional chemotherapeutic agents act by killing cells that divide rapidly, one of the main properties of most cancer cells.
This means that chemotherapy also harms cells that divide rapidly under normal circumstances: cells in the bone marrow, digestive tract, and hair follicles.
This results in the most common side-effects of chemotherapy: myelosuppression (decreased production of blood cells, hence also immunosuppression), mucositis (inflammation of the lining of the digestive tract), and alopecia (hair loss).
Some newer anticancer drugs (for example, various monoclonal antibodies) are not indiscriminately cytotoxic, but rather target proteins that are abnormally expressed in cancer cells and that are essential for their growth.
Such treatments are often referred to as targeted therapy (as distinct from classic chemotherapy) and are often used alongside traditional chemotherapeutic agents in antineoplastic treatment regimens.
Chemotherapy may use one drug at a time (single-agent chemotherapy) or several drugs at once (combination chemotherapy or polychemotherapy).
The combination of chemotherapy and radiotherapy is chemoradiotherapy.
Chemotherapy using drugs that convert to cytotoxic activity only upon light exposure is called photochemotherapy or photodynamic therapy.
An older and broader use of the word chemotherapy encompassed any chemical treatment of disease (for example, treatment of infections with antimicrobial agents).
However, this use has become archaic. 
Radiation therapy is in itself painless.
Many low-dose palliative treatments (for example, radiation therapy to bony metastases) cause minimal or no side effects, although short-term pain flare-up can be experienced in the days following treatment due to oedema compressing nerves in the treated area.
Higher doses can cause varying side effects during treatment (acute side effects), in the months or years following treatment (long-term side effects), or after re-treatment (cumulative side effects).
The nature, severity, and longevity of side effects depends on the organs that receive the radiation, the treatment itself (type of radiation, dose, fractionation, concurrent chemotherapy), and the patient.
Most side effects are predictable and expected.
Side effects from radiation are usually limited to the area of the patient's body that is under treatment.
Modern radiation therapy aims to reduce side effects to a minimum and to help the patient understand and deal with side effects that are unavoidable.
The main side effects reported are fatigue and skin irritation, like a mild to moderate sun burn.
The fatigue often sets in during the middle of a course of treatment and can last for weeks after treatment ends.
The irritated skin will heal, but may not be as elastic as it was before. 
Patients undergoing chemotherapy are administered drugs designed to kill tumor cells.
Although chemotherapy may improve overall survival in patients with the most malignant primary brain tumors, it does so in only about 20 percent of patients.
Chemotherapy is often used in young children instead of radiation, as radiation may have negative effects on the developing brain.
The decision to prescribe this treatment is based on a patient’s overall health, type of tumor, and extent of the cancer.
The toxicity and many side effects of the drugs, and the uncertain outcome of chemotherapy in brain tumors puts this treatment further down the line of treatment options with surgery and radiation therapy preferred.UCLA Neuro-Oncology publishes real-time survival data for patients with a diagnosis of glioblastoma multiforme.
They are the only institution in the United States that displays how brain tumor patients are performing on current therapies.
They also show a listing of chemotherapy agents used to treat high grade glioma tumors.