2 syllables:
-itis, bitis, citas, citis, clitus, cytus, ditas, fleitas, gitis, ictis, litas, mitis, ritus, sitis, situs, smritis, tightass, titas, titis, titus, vitas, vitis, vitus, whitis

3 syllables:
actitis, arthritis, artritis, bolbitis, bronchitis, bulbitis, bursitis, caecitis, cecitis, cheilitis, chondritis, chorditis, cloacitis, cocytus, conchitis, corditis, corneitis, coxitis, cryptitis, cyclitis, cytitis, dartitis, delightous, dermitis, desmitis, detritus, discitis, diskitis, fascitis, faucitis, gastritis, glossitis, gonitis, ileitis, invite us, lienitis, lymphitis, mammitis, mastitis, mazaitis, mephitis, metritis, moraitis, myitis, nephritis, neuritis, nymphitis, ophritis, orchitis, osteitis, ostitis, otitis, petraitis, phallitis, phlebitis, phrenitis, phyllitis, posthitis, pouchitis, proctitis, pruritis, rachitis, rectitis, rhabditis, rhachitis, rhinitis, salitis, samitis, scleritis, scrotitis, sinuitis, steatitis, strumitis, struvite us, tarsitis, thecitis, tinnitis, trachitis, trichitis, typhlitis, unitas, uveitis, vagitus, villitis, vulvitis, zemaitis

4 syllables:
adenitis, adnexitis, aerotitis, anconitis, angiitis, aphroditus, arteritis, arvanitis, balanitis, barotitis, blepharitis, capsulitis, cephalitis, ceratitis, cerebritis, cervicitis, cholangeitis, cholangitis, choroiditis, clientitis, colonitis, coronitis, dactylitis, decubitis, dermatitis, didymitis, diphtheritis, eburnitis, endangiitis, enronitis, enthesitis, ethmoiditis, expeditus, fasciitis, fibrositis, gangliitis, gaulanitis, gingivitis, glissonitis, gonarthritis, hepatitis, hepititus, heraclitus, hyalitis, hymenitis, iritis, jejunitis, keratitis, laringitis, laryngitis, limenitis, lithophytous, lymphangeitis, lymphangitis, mastoiditis, meibomitis, meningitis, meniscitis, mondayitis, mucositis, myelitis, myositis, myringitis, neuronitis, odontitis, omasitis, omentitis, omphalitis, onychitis, oophoritis, orchiditis, palatitis, panarthritis, panosteitis, panotitis, panuveitis, parotitis, petrositis, phalangitis, pharyngitis, placentitis, pleuritis, podarthritis, polyarthritis, polycleitus, polyclitus, propositus, pulmonitis, pyelitis, pyonephritis, salpingitis, sclerotitis, serositis, sigmoiditis, sinusitis, sodalitas, spondylitis, staphylitis, stomatitis, syndesmitis, synovitis, syringitis, tendonitis, tenonitis, tenontitis, tenositis, thyroiditis, tonsilitis, tracheitis, trachelitis, trachonitis, trigonitis, urarthritis, urethritis, uvulitis, vaginitis, zonulitis

5 syllables:
abomasitis, acroarthritis, acute gastritis, adenoiditis, adrenalitis, alveolitis, amnionitis, antiarthritis, arachnoiditis, arthrochondritis, blennadenitis, bronchiolitis, caenorhabditis, cholecystitis, chronic bronchitis, chronic gastritis, clitoriditis, conjunctivitis, costochondritis, cystourethritis, deferentitis, descemetitis, duodenitis, elephantitis, encephalitis, endaortitis, endocystitis, endometritis, endophlebitis, endophthalmitis, epaphroditus, ependymitis, episcleritis, epityphlitis, esophagitis, fibrochondritis, folliculitis, funiculitis, gastradenitis, gastrocolitis, gouty arthritis, hemiglossitis, hermaphroditus, hidradenitis, hydradenitis, jejunoileitis, keratoiritis, lithonephritis, mastadenitis, mesophlebitis, metrophlebitis, mononeuritis, myocarditis, myofascitis, myometritis, neurodermitis, oesophagitis, panniculitis, pansinusitis, paradenitis, parametritis, paranephritis, paraproctitis, parodontitis, periarthritis, peribronchitis, pericementitis, perichondritis, pericystitis, peridesmitis, perigastritis, perimetritis, perinephritis, perineuritis, periosteitis, periostitis, periproctitis, peritonitis, perityphlitis, polychondritis, polyneuritis, proctocolitis, pylephlebitis, pyometritis, radiculitis, rectocolitis, rhinotracheitis, scleradenitis, sesamoiditis, spondylarthritis, thrombophlebitis, vaginalitis, vesiculitis, vestibulitis

6 syllables:
achillobursitis, acrodermatitis, aerosinusitis, analysis situs, arytenoiditis, balanoposthitis, barosinusitis, blepharadenitis, blepharoadenitis, canaliculitis, cholangiolitis, dacryadenitis, dacryoadenitis, delta hepatitis, diverticulitis, endocervicitis, enterogastritis, epicondylitis, epididymitis, fibromyositis, iridocyclitis, keratoscleritis, laryngotracheitis, leptomeningitis, mediastinitis, meibomianitis, mycomyringitis, nasopharyngitis, nasosinusitis, neurochoroiditis, neurodermatitis, neuromyositis, oligoarthritis, osteoarthritis, osteochondritis, osteophlebitis, pachymeningitis, panbronchiolitis, panencephalitis, parasynovitis, parencephalitis, parenchymatitis, periadenitis, periaortitis, pericholangitis, pericolonitis, pericoronitis, perihepatitis, perimeningitis, periodontitis, periophthalmitis, periovaritis, perisalpingitis, perisigmoiditis, periurethritis, photodermatitis, photokeratitis, photoretinitis, phytodermatitis, pleurohepatitis, pododermatitis, polyadenitis, polyangiitis, polymyositis, polyserositis, proctosigmoiditis, pyelonephritis, pyomyositis, pyoperitonitis, pyosalpingitis, radioneuritis, rheumatoid arthritis, rhinopharyngitis, rhinosinusitis, rokas jokubaitis, sacroiliitis, sclerochoroiditis, sclerokeratitis, serum hepatitis, sialadenitis, sialoadenitis, sialodochitis, steatohepatitis, tendosynovitis, tendovaginitis, tenosynovitis, tenovaginitis, thrombolymphangitis, trachelomyitis, tracheobronchitis, viral hepatitis, vulvovaginitis

7 syllables:
acarodermatitis, actinodermatitis, adenopharyngitis, cephalomeningitis, cerebromeningitis, choriomeningitis, dermatomyositis, endomyocarditis, endomyometritis, enterohepatitis, erythrodermatitis, gastroduodenitis, gingivostomatitis, glomerulonephritis, hyaloserositis, infectious hepatitis, iridochoroiditis, iridokeratitis, laryngopharyngitis, leukoencephalitis, meningomyelitis, metroperitonitis, oophorosalpingitis, osteomyelitis, pelviperitonitis, periencephalitis, perifolliculitis, pharyngolaryngitis, pneumoperitonitis, poliomyelitis, pseudofolliculitis, radiodermatitis, retinochoroiditis, retroperitonitis, vasovesiculitis

8 syllables:
chorioamnionitis, cystopyelonephritis, degenerative arthritis, encephalomeningitis, encephalomyelitis, epidemic meningitis, epididymo-orchitis, hashimoto's thyroiditis, keratoconjunctivitis, lethargic encephalitis, meningoencephalitis, orchiepididymitis, osteoperiostitis, phytophotodermatitis, polioencephalitis, prostatovesiculitis

9 syllables:
encephalomyocarditis, epidemic encephalitis, juvenile rheumatoid arthritis, laryngotracheobronchitis

11 syllables:
polioencephalomyelitis

4 syllables:
recognisance, reconditeness