Antispasmodic + bulk-forming laxative Pregnancy: §4.6: should be avoided during pregnancy (limited data for ispaghula husk, no or limited data for mebeverine, animal studies insufficient). Should not be used in breast-feeding — mebeverine or its metabolites have been identified in breastfed newborns/infants of treated women. No clinical fertility data.

Mebeverine with ispaghula husk

Brand names: Fybogel Mebeverine

This combination pairs the antispasmodic mebeverine with the bulk-forming agent ispaghula husk for irritable bowel syndrome where both cramping pain and altered, particularly constipation-predominant, bowel habit are present.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: One sachet (contents stirred into a glass of cold water, at least 150 ml, and drunk immediately)

Route: Oral, as a suspension in water

Frequency: Morning and evening, taken half an hour before meals; a third dose may be taken before the midday meal if necessary

eMC §4.2 (Fybogel Mebeverine granules for oral suspension in unit dose sachet): adults and children over 12 — one sachet morning and evening, half an hour before meals; a third dose may be taken before the midday meal if necessary. Elderly: there is no indication that the dose needs to be modified. Children below 12: not recommended (§4.4 — insufficient efficacy data). The product must NOT be taken in the dry form — always mix with fluid (150 ml of water or other liquid per sachet); gastrointestinal obstruction/impaction has been reported when taken with insufficient liquid. Take at least half an hour to 1 hour before or after other medicines, and not immediately before going to sleep. Effects may take 12 to 24 hours. Avoid inhaling the powder when preparing (sensitisation risk). A doctor should be consulted if new symptoms develop, symptoms worsen, or symptoms do not improve after two weeks of treatment. Each sachet contains 16 mg aspartame (a source of phenylalanine) and 2.5 mmol (97.6 mg) potassium.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to ispaghula husk, mebeverine or any of the excipients
Sudden change in bowel habit that has persisted more than two weeks
Undiagnosed rectal bleeding, and failure to defecate following the use of a laxative
Abnormal constrictions of the gastro-intestinal tract, diseases of the oesophagus and cardia, potential or existing intestinal blockage (ileus), intestinal paralysis or megacolon
Difficulty in swallowing or any throat problems

Side effects

Hypersensitivity disorders including rash, urticaria, anaphylactic reaction, pruritus, bronchospasm, rhinitis and angioedema (frequency not known)
Flatulence and abdominal distension (bloating), often in the first few days of treatment
Intestinal obstruction, oesophageal obstruction and faecal impaction, particularly if swallowed with insufficient fluid
Conjunctivitis and rhinitis (allergen exposure, including by inhalation of the powder)
Skin rash

Interactions

§4.4: to decrease the risk of gastrointestinal obstruction (ileus), ispaghula husk should not be used together with medicinal products known to inhibit peristaltic movement (e.g. opioids), and then only under medical supervision — the full §4.5 was not retrieved in this fetch

Clinical monograph

How it works

Mebeverine relaxes intestinal smooth muscle to relieve spasm, while ispaghula husk is a soluble fibre that absorbs water to increase faecal bulk and normalise stool consistency and transit.

Prescribing in practice

Ispaghula must be taken with plenty of fluid and avoided in patients with intestinal obstruction, faecal impaction or difficulty swallowing, as inadequate fluid can cause oesophageal or bowel obstruction.
Mebeverine is contraindicated in paralytic ileus; the bulking component should not be taken immediately before lying down or going to bed.
Bulk-forming fibre may reduce absorption of some co-administered oral drugs, so timing should be considered.

Monitoring

No routine laboratory monitoring is needed; assess bowel habit and symptom response and reconsider the diagnosis if alarm features arise.

Counselling the patient

Take each dose with a full glass of water and not right before bedtime.
It may take a little time to settle your bowel pattern; keep up your fluid intake.
Report worsening pain, swallowing difficulty, bleeding or weight loss.

Evidence & guidelines

NICE supports soluble fibre such as ispaghula and antispasmodics in irritable bowel syndrome, while advising against insoluble bran, which can worsen symptoms.

Reference: NICE CG61; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways