Begin eating mild foods without spices on the second
day. These foods include plain boiled rice, dry toast,
saltines, applesauce, and bananas.
Avoid spicy foods, citrus fruits, caffeinated bever-
ages, and alcohol until two days after the last symp-
toms of giardiasis have disappeared.
Avoid milk and other dairy products for three days
after the last symptoms of giardiasis.
Patients who have developed lactose intolerance
as a result of giardiasis can usually treat the problem
themselves by avoiding milk and dairy products for a
full month (or longer) after the end of symptoms, and
then add them to the diet in small amounts on a
gradual basis. They may also wish to consider some
alternative products such assoymilk, almond milk,
oat milk, or rice milk, or try some of the lactose-free
milk and cheese products that are now available.Benefits
Medications
Anti-infective medications benefit the patient by
killing the parasites responsible for giardiasis, thereby
lowering the risk of developing chronic giardiasis and
malabsorption syndrome.Dietary treatment
Dietary treatment for giardiasis benefits the
patient by giving the digestive tract a rest and by
replacing nutrients and electrolytes lost by acute diar-
rhea or vomiting.Precautions
Medications
Patients taking anti-infective drugs should tell
their doctor about any other medications they may
be taking, including over-the-counter drugs, to lower
the risk of drug interactions.
Pregnant women should not take any anti-infec-
tive medication for giardiasis except paramomycin,
and then only if they are severely ill.
Anti-infective medications should be taken with
food to lower the risk of nausea or heartburn. They
should, however,neverbe taken with alcohol, as they
will interact to cause severe nausea and vomiting.
Alcoholic beverages should be avoided for at least 48
hours after the last dose of the medication.Preventive dietary and public health measures
The risk of contracting giardiasis can be lowered
by simple dietary and personal cleanliness measures:Avoid drinking untreated or unpurified water when
hiking or camping. Boil the water for at least 1 full
minute or add commercial purification tablets before
drinking.
When traveling in other countries known to have
high rates of giardiasis, drink only bottled water
and do not eat raw fruits or vegetables or drink
beverages containing ice made from untreated
water. The CDC maintains a frequently updated
list of travelers’ advisories on its website.
Wash hands often, particularly after using the toilet,
changing diapers, helping someone else use the toilet,
or before food preparation.
Avoid swallowing water when swimming in lakes,
rivers, or streams.
Protect others by avoiding swimming pools, hot
tubs, the ocean, or lakes and streams while infected
withG. lamblia, and for at least 2 weeks after the
diarrhea stops. It is possible to pass the organism in
stool and contaminate water for several weeks after
the symptoms have ended.
Avoid exposure to fecal material during sexual
activity.Risks
Medications
The anti-infective drugs listed above cause some
adverse effects in some patients, including nausea,
constipation, headache, temporary discoloration of
the urine, a metallic taste in the mouth, drowsiness,
skin rashes or itching, dry mouth, or depression.
Anti-infective medications interact with such
other drugs as cimetidine, praziquantel, tricyclic anti-
depressants, selective serotonin reuptake inhibitors
(SSRIs), lithium, phenytoin, and others. They coun-
teract the effects of some of these medications and
intensify the effects of others.Dietary treatment
There are no risks associated with modifying the
patient’s normal diet as part of recovery from giardiasis.QUESTIONS TO ASK YOUR
DOCTOR What can I do to prevent giardiasis in my
household?
What precautions would you advise before a
family vacation trip?Giardiasis